National Bank (NBHC) 10-Q 8 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	7-May-15
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	NBHC
Entity Registrant Name	National Bank Holdings Corp
Entity Central Index Key	1475841
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Common Class A [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		36,046,682
Common Class B [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		343,929

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Condition (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
ASSETS
Cash and due from banks	$52,797	$61,461
Due from Federal Reserve Bank of Kansas City	427,239	185,463
Interest bearing bank deposits	10,068	10,055
Cash and cash equivalents	490,104	256,979
Investment securities available-for-sale (at fair value)	1,413,414	1,479,214
Investment securities held-to-maturity (fair value of $510,803 and $534,637 at March 31, 2015 and December 31, 2014, respectively)	503,610	530,590
Non-marketable securities	27,050	27,045
Loans (including covered loans of $171,887 and $193,697 at March 31, 2015 and December 31, 2014, respectively)	2,216,269	2,162,409
Allowance for loan losses	-18,873	-17,613
Loans, net	2,197,396	2,144,796
Loans held for sale	4,935	5,146
Federal Deposit Insurance Corporation (“FDIC”) indemnification asset, net	27,854	39,082
Other real estate owned	23,417	29,120
Premises and equipment, net	104,334	106,341
Goodwill	59,630	59,630
Intangible assets, net	15,546	16,883
Other assets	123,760	124,820
Total assets	4,991,050	4,819,646
Liabilities:
Non-interest bearing demand deposits	758,763	732,580
Interest bearing demand deposits	390,523	386,121
Savings and money market	1,358,515	1,290,436
Time deposits	1,324,661	1,357,051
Total deposits	3,832,462	3,766,188
Securities sold under agreements to repurchase	284,161	133,552
Advances from Federal Home Loan Banks	40,000	40,000
Due to FDIC	37,813	42,011
Other liabilities	33,938	43,320
Total liabilities	4,228,374	4,025,071
Shareholders’ equity:
Common stock, par value $0.01 per share: 400,000,000 shares authorized; 52,221,999 and 52,223,460 shares issued; 36,797,787 and 38,884,953 shares outstanding at March 31, 2015 and December 31, 2014, respectively	512	512
Additional paid in capital	993,874	993,212
Retained earnings	39,866	40,528
Treasury stock of 14,470,275 and 12,383,109 shares at March 31, 2015 and December 31, 2014, respectively, at cost	-283,661	-245,516
Accumulated other comprehensive income, net of tax	12,085	5,839
Total shareholders’ equity	762,676	794,575
Total liabilities and shareholders’ equity	$4,991,050	$4,819,646

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Condition (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Investment securities held-to-maturity, fair value	$510,803	$534,637
Loans receivable, net - covered		$193,697
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	52,221,999	52,223,460
Common Stock, shares outstanding	36,797,787	38,884,953
Treasury stock, shares	14,470,275	12,383,109

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Interest and dividend income:
Interest and fees on loans	$31,981	$33,247
Interest and dividends on investment securities	10,572	13,168
Dividends on non-marketable securities	327	389
Interest on interest-bearing bank deposits	207	81
Total interest and dividend income	43,087	46,885
Interest expense:
Interest on deposits	3,399	3,506
Interest on borrowings	209	32
Total interest expense	3,608	3,538
Net interest income before provision for loan losses	39,479	43,347
Provision for loan losses	1,453	1,769
Net interest income after provision for loan losses	38,026	41,578
Non-interest income:
FDIC indemnification asset amortization	-7,670	-7,608
FDIC loss sharing expense	-810	-957
Service charges	3,327	3,540
Bank card fees	2,550	2,374
Gain on sales of mortgages, net	400	208
Bank Owned Life Insurance Income	394	0
Other non-interest income	772	825
Gain on previously charged-off acquired loans	58	296
Other real estate owned related write-ups and other income	500	968
Total non-interest income (expense)	-479	-354
Non-interest expense:
Salaries and benefits	20,077	20,774
Occupancy and equipment	6,089	6,474
Telecommunications and data processing	3,062	3,148
Marketing and business development	1,009	1,023
FDIC deposit insurance	1,041	1,045
ATM/debit card expenses	757	751
Professional fees	1,120	638
Other non-interest expense	2,242	2,409
Gain (loss) from the change in fair value of warrant liability	-390	-898
Intangible asset amortization	1,336	1,336
Other real estate owned (income) expenses	-418	1,633
Problem loan expenses	799	685
Total non-interest expense	36,724	39,018
Income before income taxes	823	2,206
Income tax expense	-423	775
Net income	$1,246	$1,431
Income per share—basic (in dollars per share)	$0.03	$0.03
Income per share—diluted (in dollars per share)	$0.03	$0.03
Weighted average number of common shares outstanding:
Basic (Shares)	38,028,506	44,819,644
Diluted (Shares)	38,028,612	44,863,138

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$1,246	$1,431
Other comprehensive income, net of tax:
Net unrealized gains arising during the period, net of tax expense of $4,298 and $4,962 for the three months ended March 31, 2015 and 2014, respectively.	6,988	8,070
Securities available for sale, net	6,988	8,070
Net unrealized holding gains on securities transferred between available-for-sale to held-to-maturity:
Amortization of net unrealized holding gains on securities transferred between available-for-sale to held-to-maturity, net of tax benefit of $457 and $519 for the three months ended March 31, 2015 and 2014, respectively.	-742	-845
Other comprehensive income, net	-742	-845
Other comprehensive income	6,246	7,225
Comprehensive income	$7,492	$8,656

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Tax expense on net unrealized gains arising during the period	($4,298)	($4,962)
Tax benefit of amortization of net unrealized holding gains to income	$457	$519

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, 2013	$897,792	$512	$990,216	$39,966	($126,146)	($6,756)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,431	0	0	1,431	0	0
Stock-based compensation	720	0	720	0	0	0
Issuance under equity compensation plan	-236	0	-236	0	0	0
Repurchase of shares	-8,807	0	0	0	-8,807	0
Dividends paid ($0.05 per share)	-2,276	0	0	-2,276	0	0
Other comprehensive income	7,225	0	0	0	0	7,225
Balance in the ending at Mar. 31, 2014	895,849	512	990,700	39,121	-134,953	469
Balance in the beginning at Dec. 31, 2014	794,575	512	993,212	40,528	-245,516	5,839
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,246	0	0	1,246	0	0
Stock-based compensation	665	0	665	0	0	0
Change in corporate tax benefit related to stock-based compensation	-3	0	-3	0	0	0
Repurchase of shares	-38,145	0	0	0	-38,145	0
Dividends paid ($0.05 per share)	-1,908	0	0	-1,908	0	0
Other comprehensive income	6,246	0	0	0	0	6,246
Balance in the ending at Mar. 31, 2015	$762,676	$512	$993,874	$39,866	($283,661)	$12,085

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Dividends paid per share	$0.05	$0.05
Common Stock Purchased	2,087,166	454,706
Treasury Stock, Shares, Retired	0	0

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$1,246	$1,431
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for loan losses	1,453	1,769
Depreciation and amortization	3,876	4,180
Current income tax receivable	-366	6,017
Deferred income tax asset	4	-4,584
Discount accretion, net of premium amortization on securities	1,049	1,320
Loan accretion	-13,204	-17,733
Net gain on sale of mortgage loans	-400	-208
Origination of loans held for sale, net of repayments	-17,634	-6,506
Proceeds from sales of loans held for sale	18,245	9,742
Bank Owned Life Insurance Income	-394	0
Amortization of indemnification asset	7,670	7,608
Gain on the sale of other real estate owned, net	-1,471	-587
Impairment on other real estate owned	470	822
Gain on sale of fixed assets	0	-118
Stock-based compensation	665	720
Decrease in due to FDIC, net	-4,198	-8,573
Increase in other assets	-2,025	-1,451
Decrease in other liabilities	-9,419	-9,355
Net cash used in operating activities	-14,433	-15,506
Cash flows from investing activities:
Proceeds from redemption of FHLB stock	234	554
Payments to Acquire Federal Reserve Bank Stock	-239	0
Maturities of investment securities held-to-maturity	25,636	24,190
Maturities of investment securities available-for-sale	76,182	76,532
Net increase in loans	-53,049	-90,125
Purchase of premises and equipment, net	-532	-41
Proceeds from sales of loans	11,702	422
Proceeds from sales of other real estate owned	7,202	4,143
Increase in FDIC indemnification asset	3,558	162
Net cash provided by investing activities	70,694	15,837
Cash flows from financing activities:
Net increase in deposits	66,274	27,787
Increase in repurchase agreements	150,609	-8,482
Issuance under equity compensation plan	0	-236
Excess Tax Benefit from Share-based Compensation, Financing Activities	-3	0
Payment of dividends	-1,871	-2,238
Repurchase of shares	-38,145	-8,807
Net cash provided by financing activities	176,864	8,024
Increase in cash and cash equivalents	233,125	8,355
Cash and cash equivalents at beginning of the year	256,979	189,460
Cash and cash equivalents at end of period	490,104	197,815
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	3,412	3,484
(Refunds received) cash paid during the period for taxes	-73	-638
Supplemental schedule of non-cash investing activities:
Loans transferred to other real estate owned at fair value	498	236
FDIC indemnification asset claims transferred to (other liabilities) other assets	-1,342	29
Loans purchased but not settled	$0	$397

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	National Bank Holdings Corporation ("NBHC" or 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 financial services franchises and other complementary businesses in targeted markets. The Company is headquartered immediately south of Denver, in Greenwood Village, Colorado, and its primary operations are conducted through its wholly owned subsidiary, NBH Bank, N.A. (the "Bank"). The Company provides a variety of banking products to both commercial and consumer clients through a network of 97 banking centers located in Colorado, the greater Kansas City area and Texas, and through on-line and mobile banking products.
	The accompanying interim consolidated financial statements serve to update the National Bank Holdings Corporation Annual Report on Form 10-K for the year ended December 31, 2014 and include the accounts of the Company and the Bank. The accompanying consolidated 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 Company's most recent Form 10-K. The consolidated 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 period is 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 consolidated financial statements are disclosed in note 2 of the audited financial statements and notes for the year ended December 31, 2014 and are contained in the Company's Annual Report on Form 10-K. There have not been any significant changes to the application of significant accounting policies since December 31, 2014. 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 valuation of stock-based compensation, 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.

Investment_Securities

Investment Securities	3 Months Ended
	Mar. 31, 2015
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 $1.9 billion at March 31, 2015 and $2.0 billion at December 31, 2014. Included in the aforementioned $1.9 billion was $1.4 billion of available-for-sale securities and $0.5 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):
		March 31, 2015
		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	$	373,802	$	11,434		$	—		$	385,236
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	1,033,190		7,972			(13,403		)	1,027,759
	Other securities	419		—			—			419
	Total	$	1,407,411	$	19,406		$	(13,403	)	$	1,413,414
		December 31, 2014
		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	$	395,244	$	9,014		$	(43	)	$	404,215
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	1,088,834		7,464			(21,718		)	1,074,580
	Other securities	419		—			—			419
	Total	$	1,484,497	$	16,478		$	(21,761	)	$	1,479,214
	At March 31, 2015 and December 31, 2014, mortgage-backed securities represented primarily all 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):
		March 31, 2015
		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	$	—	$	—		$	—		$	—		$	—	$	—
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	75,887		(1,305		)	611,431			(12,098		)	687,318		(13,403		)
	Total	$	75,887	$	(1,305	)	$	611,431		$	(12,098	)	$	687,318	$	(13,403	)
		December 31, 2014
		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	$	—		$	89,749		$	(43	)	$	89,766	$	(43	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	88,854		(2,053		)	667,368			(19,665		)	756,222		(21,718		)
	Total	$	88,871	$	(2,053	)	$	757,117		$	(19,708	)	$	845,988	$	(21,761	)
	Management evaluated all of the available-for-sale securities in an unrealized loss position and concluded that no other-than-temporary impairment existed at March 31, 2015 or December 31, 2014. The unrealized losses in the Company's investments issued or guaranteed by U.S. government agencies or sponsored enterprises at March 31, 2015 were caused by changes in interest rates. 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.
	Certain securities are pledged 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 $446.8 million at March 31, 2015 and $274.4 million December 31, 2014. The increase in pledged available-for-sale investment securities was primarily attributable to an increase in average deposit account balances and client repurchase account balances during the three months ended March 31, 2015, and an increase in pledged securities for derivative instruments. Certain investment securities may also be pledged as collateral for the line of credit at the Federal Home Loan Bank ("FHLB") of Des Moines; however, no investment securities were pledged for this purpose at March 31, 2015 or December 31, 2014.
	Mortgage-backed securities do not have a single maturity date and actual maturities 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 3.3 years as of March 31, 2015 and 3.5 years as of December 31, 2014. 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 March 31, 2015.
	Held-to-maturity
	At March 31, 2015 and December 31, 2014, the Company held $503.6 million and $530.6 million of held-to-maturity investment securities, respectively. Held-to-maturity investment securities are summarized as follows as of the dates indicated (in thousands):
		March 31, 2015
		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	$	400,408	$	7,860		$	(17	)	$	408,251
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	103,202		499			(1,149		)	102,552
	Total investment securities held-to-maturity	$	503,610	$	8,359		$	(1,166	)	$	510,803
		December 31, 2014
		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	$	422,622	$	5,773		$	(72	)	$	428,323
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	107,968		217			(1,871		)	106,314
	Total investment securities held-to-maturity	$	530,590	$	5,990		$	(1,943	)	$	534,637
	The table below summarizes the unrealized losses as of the dates shown, along with the length of the impairment period (in thousands):
		March 31, 2015
		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	$	—	$	—		$	2,120		$	(17	)	$	2,120	$	(17	)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		—			52,949			(1,149		)	52,949		(1,149		)
Total	$	—	$	—		$	55,069		$	(1,166	)	$	55,069	$	(1,166	)
	December 31, 2014
	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	$	—	$	—		$	35,139		$	(72	)	$	35,139	$	(72	)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		—			75,139			(1,871		)	75,139		(1,871		)
Total	$	—	$	—		$	110,278		$	(1,943	)	$	110,278	$	(1,943	)
Management evaluated all of the held-to-maturity securities in an unrealized loss position and concluded that no other-than-temporary impairment existed at March 31, 2015 or December 31, 2014. The unrealized losses in the Company's investments issued or guaranteed by U.S. government agencies or sponsored enterprises at March 31, 2015 were caused by changes in interest rates. 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 carrying value of held-to-maturity investment securities pledged as collateral totaled $99.5 million and $88.3 million at March 31, 2015 and December 31, 2014, 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 March 31, 2015 and December 31, 2014 was 3.2 years and 3.4 years, respectively. This estimate is based on assumptions and actual results may differ.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure - In January 2014, the FASB issued Accounting Standards Update ("ASU") 2014-04, “Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure.” This update amends ASC Topic 310-40 and clarifies that an “in substance repossession or foreclosure” has occurred upon the creditor obtaining either legal title to the property upon completion of foreclosure, or the borrower conveying all interest in the property through completion of a deed in lieu of foreclosure. Upon occurrence, the creditor derecognizes the loan receivable and recognizes the collateralized real estate property. The amendments in the ASU became effective for the Company for interim and annual periods beginning after December 15, 2014. Early adoption was permitted. Adoption of this amendment can be made using either a modified retrospective transition method or a prospective transition method. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity.
	Revenue from Contracts with Customers - In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers." This update supersedes revenue recognition requirements in Topic 605, Revenue Recognition, including most industry-specific revenue recognition guidance in the FASB Accounting Standards Codification. The new guidance stipulates that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides specific steps that entities should apply in order to achieve this principle. The amendments are effective for interim and annual periods beginning January 1, 2017 and must be applied retrospectively. The Company is in the process of evaluating the impact of the ASU's adoption on the Company's consolidated financial statements.

Loans

Loans	3 Months Ended
	Mar. 31, 2015
Receivables [Abstract]
Loans	Loans
	The loan portfolio is comprised of 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 7.8% of the total loan portfolio at March 31, 2015, compared to 9.0% of the total loan portfolio at December 31, 2014.
	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 March 31, 2015 and December 31, 2014. 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 $9.5 million and $10.5 million as of March 31, 2015 and December 31, 2014, respectively (in thousands):
		March 31, 2015
		ASC 310-30			Non 310-30			Total loans		% of total
		loans			loans
	Commercial	$	21,481		$	832,724		$	854,205	38.5	%
	Agriculture	19,067			113,608			132,675		6	%
	Commercial real estate	171,742			388,833			560,575		25.3	%
	Residential real estate	33,158			602,904			636,062		28.7	%
	Consumer	4,406			28,346			32,752		1.5	%
	Total	$	249,854		$	1,966,415		$	2,216,269	100	%
	Covered	$	142,345		$	29,542		$	171,887	7.8	%
	Non-covered	107,509			1,936,873			2,044,382		92.2	%
	Total	$	249,854		$	1,966,415		$	2,216,269	100	%
		December 31, 2014
		ASC 310-30			Non 310-30			Total loans		% of total
		loans			loans
	Commercial	$	22,956		$	772,440		$	795,396	36.8	%
	Agriculture	19,063			118,468			137,531		6.4	%
	Commercial real estate	192,330			369,264			561,594		26	%
	Residential real estate	40,761			591,939			632,700		29.2	%
	Consumer	4,535			30,653			35,188		1.6	%
	Total	$	279,645		$	1,882,764		$	2,162,409	100	%
	Covered	$	160,876		$	32,821		$	193,697	9	%
	Non-covered	118,769			1,849,943			1,968,712		91	%
	Total	$	279,645		$	1,882,764		$	2,162,409	100	%
	Included in commercial loans are $149.6 million and $161.8 million of energy-related loans at March 31, 2015 and December 31, 2014, respectively. Energy prices declined significantly during 2014 and prolonged or further pricing pressure could increase stress on energy clients and ultimately the credit quality of this portfolio. However, loans have been structured to mitigate credit loss under a variety of circumstances, including the impact on energy loans as a result of depressed oil prices for a sustained period. Also included in the commercial segment are loans originated by the Company's specialty commercial banking groups. These loans totaled $194.6 million and $130.6 million at March 31, 2015 and December 31, 2014, respectively. At March 31, 2015 and December 31, 2014, $176.6 million and $112.6 million, respectively, of the loans were tax-exempt.
	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. 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. Non-accrual loans include troubled debt restructurings on non-accrual status. At March 31, 2015 and December 31, 2014, $11.4 million and $10.8 million, respectively, of loans excluded from the scope of ASC 310-30 were on non-accrual. Loan delinquency for all loans is shown in the following tables at March 31, 2015 and December 31, 2014, respectively (in thousands):
		Total Loans March 31, 2015
		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	$	306		$	71		$	1,142	$	1,519	$	831,205	$	832,724	$	81		$	4,803
	Agriculture	—			36			33		69		113,539		113,608		—			396
	Commercial real estate
	Construction	—			—			—		—		6,718		6,718		—			—
	Acquisition/development	—			—			—		—		4,098		4,098		—			—
	Multifamily	—			—			—		—		17,324		17,324		(1		)	—
	Owner-occupied	57			146			116		319		132,873		133,192		—			778
	Non owner-occupied	105			51			220		376		227,125		227,501		—			220
	Total commercial real estate	162			197			336		695		388,138		388,833		(1		)	998
	Residential real estate
	Senior lien	363			85			653		1,101		550,056		551,157		—			4,438
	Junior lien	24			18			180		222		51,525		51,747		88			509
	Total residential real estate	387			103			833		1,323		601,581		602,904		88			4,947
	Consumer	196			1			189		386		27,960		28,346		6			214
	Total loans excluded from ASC 310-30	$	1,051		$	408		$	2,533	$	3,992	$	1,962,423	$	1,966,415	$	174		$	11,358
	Covered loans excluded from ASC 310-30	$	—		$	48		$	227	$	275	$	29,267	$	29,542	$	75		$	1,154
	Non-covered loans excluded from ASC 310-30	1,051			360			2,306		3,717		1,933,156		1,936,873		99			10,204
	Total loans excluded from ASC 310-30	$	1,051		$	408		$	2,533	$	3,992	$	1,962,423	$	1,966,415	$	174		$	11,358
	Loans accounted for under ASC 310-30
	Commercial	$	275		$	—		$	1,771	$	2,046	$	19,435	$	21,481	$	1,771		$	—
	Agriculture	21			—			380		401		18,666		19,067		379			—
	Commercial real estate	157			170			22,263		22,590		149,152		171,742		22,263			—
	Residential real estate	684			254			335		1,273		31,885		33,158		335			—
	Consumer	173			4			49		226		4,180		4,406		49			—
	Total loans accounted for under ASC 310-30	$	1,310		$	428		$	24,798	$	26,536	$	223,318	$	249,854	$	24,797		$	—
	Covered loans accounted for under ASC 310-30	$	391		$	44		$	22,276	$	22,711	$	119,634	$	142,345	$	22,276		$	—
	Non-covered loans accounted for under ASC 310-30	919			384			2,522		3,825		103,684		107,509		2,521			—
	Total loans accounted for under ASC 310-30	$	1,310		$	428		$	24,798	$	26,536	$	223,318	$	249,854	$	24,797		$	—
Total loans	$	2,361		$	836		$	27,331	$	30,528	$	2,185,741	$	2,216,269	$	24,971		$	11,358
Covered loans	$	391		$	92		$	22,503	$	22,986	$	148,901	$	171,887	$	22,351		$	1,154
Non-covered loans	1,970			744			4,828		7,542		2,036,840		2,044,382		2,620			10,204
Total loans	$	2,361		$	836		$	27,331	$	30,528	$	2,185,741	$	2,216,269	$	24,971		$	11,358
	Total Loans December 31, 2014
	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	$	83		$	97		$	318	$	498	$	771,942	$	772,440	$	215		$	4,215
Agriculture	47			—			10		57		118,411		118,468		10			495
Commercial real estate
Construction	—			—			—		—		11,748		11,748		—			—
Acquisition/development	41			—			—		41		4,532		4,573		—			—
Multifamily	—			—			—		—		10,856		10,856		(1		)	—
Owner-occupied	336			78			101		515		119,710		120,225		—			843
Non owner-occupied	158			—			222		380		221,482		221,862		—			222
Total commercial real estate	535			78			323		936		368,328		369,264		(1		)	1,065
Residential real estate
Senior lien	378			1,403			732		2,513		537,022		539,535		—			4,335
Junior lien	133			1			101		235		52,169		52,404		—			476
Total residential real estate	511			1,404			833		2,748		589,191		591,939		—			4,811
Consumer	266			21			39		326		30,327		30,653		39			227
Total loans excluded from ASC 310-30	$	1,442		$	1,600		$	1,523	$	4,565	$	1,878,199	$	1,882,764	$	263		$	10,813
Covered loans excluded from ASC 310-30	$	17		$	1,016		$	152	$	1,185	$	31,636	$	32,821	$	75		$	1,317
Non-covered loans excluded from ASC 310-30	1,425			584			1,371		3,380		1,846,563		1,849,943		188			9,496
Total loans excluded from ASC 310-30	$	1,442		$	1,600		$	1,523	$	4,565	$	1,878,199	$	1,882,764	$	263		$	10,813
Loans accounted for under ASC 310-30
Commercial	$	152		$	—		$	1,755	$	1,907	$	21,049	$	22,956	$	1,754		$	—
Agriculture	—			—			367		367		18,696		19,063		367			—
Commercial real estate	564			92			31,013		31,669		160,661		192,330		31,013			—
Residential real estate	2,014			3,826			646		6,486		34,275		40,761		646			—
Consumer	369			—			54		423		4,112		4,535		54			—
Total loans accounted for under ASC 310-30	$	3,099		$	3,918		$	33,835	$	40,852	$	238,793	$	279,645	$	33,834		$	—
Covered loans accounted for under ASC 310-30	$	576		$	3,892		$	31,239	$	35,707	$	125,169	$	160,876	$	31,238		$	—
Non-covered loans accounted for under ASC 310-30	2,523			26			2,596		5,145		113,624		118,769		2,596			—
Total loans accounted for under ASC 310-30	$	3,099		$	3,918		$	33,835	$	40,852	$	238,793	$	279,645	$	33,834		$	—
Total loans	$	4,541		$	5,518		$	35,358	$	45,417	$	2,116,992	$	2,162,409	$	34,097		$	10,813
Covered loans	$	593		$	4,908		$	31,391	$	36,892	$	156,805	$	193,697	$	31,313		$	1,317
Non-covered loans	3,948			610			3,967		8,525		1,960,187		1,968,712		2,784			9,496
Total loans	$	4,541		$	5,518		$	35,358	$	45,417	$	2,116,992	$	2,162,409	$	34,097		$	10,813
Credit exposure for all loans as determined by the Company’s internal risk rating system was as follows as of March 31, 2015 and December 31, 2014, respectively (in thousands):
	Total Loans March 31, 2015
	Pass			Special			Substandard		Doubtful		Total
				mention
Loans excluded from ASC 310-30
Commercial	$	791,459		$	22,549		$	17,992	$	724	$	832,724
Agriculture	111,118			1,599			891		—		113,608
Commercial real estate
Construction	6,718			—			—		—		6,718
Acquisition/development	4,098			—			—		—		4,098
Multifamily	17,324			—			—		—		17,324
Owner-occupied	128,289			154			4,749		—		133,192
Non owner-occupied	206,603			17,408			3,483		7		227,501
Total commercial real estate	363,032			17,562			8,232		7		388,833
Residential real estate
Senior lien	545,049			—			5,951		157		551,157
Junior lien	50,435			—			1,298		14		51,747
Total residential real estate	595,484			—			7,249		171		602,904
Consumer	28,131			—			215		—		28,346
Total loans excluded from ASC 310-30	$	1,889,224		$	41,710		$	34,579	$	902	$	1,966,415
Covered loans excluded from ASC 310-30	$	18,097		$	167		$	11,180	$	98	$	29,542
Non-covered loans excluded from ASC 310-30	1,871,127			41,543			23,399		804		1,936,873
Total loans excluded from ASC 310-30	$	1,889,224		$	41,710		$	34,579	$	902	$	1,966,415
Loans accounted for under ASC 310-30
Commercial	$	10,148		$	217		$	10,555	$	561	$	21,481
Agriculture	16,827			31			2,209		—		19,067
Commercial real estate	77,116			3,629			87,228		3,769		171,742
Residential real estate	24,415			1,258			7,485		—		33,158
Consumer	3,599			100			707		—		4,406
Total loans accounted for under ASC 310-30	$	132,105		$	5,235		$	108,184	$	4,330	$	249,854
Covered loans accounted for under ASC 310-30	$	47,426		$	2,912		$	87,677	$	4,330	$	142,345
Non-covered loans accounted for under ASC 310-30	84,679			2,323			20,507		—		107,509
Total loans accounted for under ASC 310-30	$	132,105		$	5,235		$	108,184	$	4,330	$	249,854
Total loans	$	2,021,329		$	46,945		$	142,763	$	5,232	$	2,216,269
Total covered	$	65,523		$	3,079		$	98,857	$	4,428	$	171,887
Total non-covered	1,955,806			43,866			43,906		804		2,044,382
Total loans	$	2,021,329		$	46,945		$	142,763	$	5,232	$	2,216,269
	Total Loans December 31, 2014
	Pass			Special			Substandard		Doubtful		Total
				mention
Loans excluded from ASC 310-30
Commercial	$	742,944		$	10,166		$	19,250	$	80	$	772,440
Agriculture	114,642			85			3,741		—		118,468
Commercial real estate
Construction	11,748			—			—		—		11,748
Acquisition/development	4,573			—			—		—		4,573
Multifamily	10,856			—			—		—		10,856
Owner-occupied	115,178			158			4,889		—		120,225
Non owner-occupied	199,817			17,607			4,430		8		221,862
Total commercial real estate	342,172			17,765			9,319		8		369,264
Residential real estate
Senior lien	533,630			23			5,744		138		539,535
Junior lien	51,059			—			1,345		—		52,404
Total residential real estate	584,689			23			7,089		138		591,939
Consumer	30,426			—			227		—		30,653
Total loans excluded from ASC 310-30	$	1,814,873		$	28,039		$	39,626	$	226	$	1,882,764
Covered loans excluded from ASC 310-30	$	21,240		$	171		$	11,301	$	109	$	32,821
Non-covered loans excluded from ASC 310-30	1,793,633			27,868			28,325		117		1,849,943
Total loans excluded from ASC 310-30	$	1,814,873		$	28,039		$	39,626	$	226	$	1,882,764
Loans accounted for under ASC 310-30
Commercial	$	11,038		$	282		$	11,092	$	544	$	22,956
Agriculture	16,854			30			2,179		—		19,063
Commercial real estate	82,603			3,770			101,966		3,991		192,330
Residential real estate	29,069			1,403			10,289		—		40,761
Consumer	3,641			105			789		—		4,535
Total loans accounted for under ASC 310-30	$	143,205		$	5,590		$	126,315	$	4,535	$	279,645
Covered loans accounted for under ASC 310-30	$	49,856		$	3,036		$	103,451	$	4,533	$	160,876
Non-covered loans accounted for under ASC 310-30	93,349			2,554			22,864		2		118,769
Total loans accounted for under ASC 310-30	$	143,205		$	5,590		$	126,315	$	4,535	$	279,645
Total loans	$	1,958,078		$	33,629		$	165,941	$	4,761	$	2,162,409
Total covered	$	71,096		$	3,207		$	114,752	$	4,642	$	193,697
Total non-covered	1,886,982			30,422			51,189		119		1,968,712
Total loans	$	1,958,078		$	33,629		$	165,941	$	4,761	$	2,162,409
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. Impaired loans are comprised of 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 March 31, 2015, the Company measured $3.9 million of impaired loans using discounted cash flows and the loan’s initial contractual effective interest rate and $17.3 million of impaired loans based on the fair value of the collateral less selling costs. Impaired loans totaling $9.7 million that individually were less than $250 thousand each, were measured through our general ALL reserves due to their relatively small size.
At March 31, 2015 and December 31, 2014, the Company’s recorded investments in impaired loans was $30.9 million and $32.1 million, respectively, of which $11.0 million and $11.1 million, respectively, were covered by loss sharing agreements, for the aforementioned periods. Impaired loans had a collective related allowance for loan losses allocated to them of $0.9 million and $0.3 million at March 31, 2015 and December 31, 2014, respectively. Additional information regarding impaired loans at March 31, 2015 and December 31, 2014 is set forth in the table below (in thousands):
	Impaired Loans
	March 31, 2015								December 31, 2014
	Unpaid			Recorded			Allowance		Unpaid		Recorded		Allowance
	principal			investment			for loan		principal		investment		for loan
	balance						losses		balance				losses
							allocated						allocated
With no related allowance recorded:
Commercial	$	16,485		$	16,290		$	—	$	16,953	$	16,771	$	—
Agriculture	—			—			—		3,065		3,061		—
Commercial real estate
Construction	—			—			—		—		—		—
Acquisition/development	—			—			—		—		—		—
Multifamily	—			—			—		—		—		—
Owner-occupied	2,188			1,923			—		1,164		970		—
Non-owner occupied	—			—			—		—		—		—
Total commercial real estate	2,188			1,923			—		1,164		970		—
Residential real estate
Senior lien	354			316			—		694		248		—
Junior lien	—			—			—		—		—		—
Total residential real estate	354			316			—		694		248		—
Consumer	—			—			—		—		—		—
Total impaired loans with no related allowance recorded	$	19,027		$	18,529		$	—	$	21,876	$	21,050	$	—
With a related allowance recorded:
Commercial	$	1,720		$	1,528		$	725	$	894	$	693	$	82
Agriculture	555			495			2		177		145		—
Commercial real estate
Construction	—			—			—		—		—		—
Acquisition/development	—			—			—		—		—		—
Multifamily	40			39			—		—		—		—
Owner-occupied	1,275			965			3		1,321		1,024		5
Non-owner occupied	1,120			1,037			8		1,140		1,060		9
Total commercial real estate	2,435			2,041			11		2,461		2,084		14
Residential real estate
Senior lien	7,508			6,547			180		7,360		6,359		172
Junior lien	1,785			1,527			22		1,768		1,515		9
Total residential real estate	9,293			8,074			202		9,128		7,874		181
Consumer	268			231			2		277		245		2
Total impaired loans with a related allowance recorded	$	14,271		$	12,369		$	942	$	12,937	$	11,041	$	279
Total impaired loans	$	33,298		$	30,898		$	942	$	34,813	$	32,091	$	279
The table below shows additional information regarding the average recorded investment and interest income recognized on impaired loans for the periods presented (in thousands):
	For the three months ended
	31-Mar-15						31-Mar-14
	Average recorded investment			Interest income recognized			Average recorded investment		Interest income recognized
With no related allowance recorded:
Commercial	$	16,252		$	176		$	7,562	$	94
Agriculture	—			—			9,132		119
Commercial real estate
Construction	—			—			—		—
Acquisition/development	—			—			398		5
Multifamily	—			—			908		—
Owner-occupied	1,935			25			1,622		26
Non owner-occupied	—			—			480		8
Total commercial real estate	1,935			25			3,408		39
Residential real estate
Senior lien	319			—			701		4
Junior lien	—			—			—		—
Total residential real estate	319			—			701		4
Consumer	—			—			—		—
Total impaired loans with no related allowance recorded	$	18,506		$	201		$	20,803	$	256
With a related allowance recorded:
Commercial	$	1,544		$	—		$	2,113	$	12
Agriculture	583			—			177		—
Commercial real estate
Construction	—			—			—		—
Acquisition/development	—			—			—		—
Multifamily	40			—			165		—
Owner-occupied	986			7			879		3
Non owner-occupied	1,045			13			625		7
Total commercial real estate	2,071			20			1,669		10
Residential real estate
Senior lien	6,598			27			7,243		27
Junior lien	1,539			14			1,566		15
Total residential real estate	8,137			41			8,809		42
Consumer	235			—			250		—
Total impaired loans with a related allowance recorded	$	12,570		$	61		$	13,018	$	64
Total impaired loans	$	31,076		$	262		$	33,821	$	320
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 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 TDR. At March 31, 2015 and December 31, 2014, the Company had $8.7 million and $19.3 million, respectively, of accruing TDRs that had been restructured from the original terms in order to facilitate repayment. Of these, $1.8 million and $9.8 million, respectively, were covered by FDIC loss sharing agreements. Approximately $8.8 million of loans reported as TDRs at December 31, 2014 were in compliance with their modified terms at March 31, 2015, and therefore, are no longer reportable as TDRs at March 31, 2015.
Non-accruing TDRs at March 31, 2015 and December 31, 2014 totaled $6.5 million and $7.0 million, respectively. Of these, $1.1 million and $1.2 million were covered by the FDIC loss sharing agreements as of March 31, 2015 and December 31, 2014, respectively.
During the three months ended March 31, 2015, the Company restructured nine loans with a recorded investment of $1.2 million to facilitate repayment. Substantially all of the loan modifications were an extension of term. Loan modifications to loans accounted for under ASC 310-30 are not considered TDRs. The table below provides additional information related to accruing TDRs at March 31, 2015 and December 31, 2014 (in thousands):
	Accruing TDRs
	31-Mar-15
	Recorded			Average			Unpaid		Unfunded
	investment			year-to-			principal		commitments
				date			balance		to fund
				recorded					TDRs
				investment
Commercial	$	5,015		$	4,868		$	5,015	$	35
Agriculture	99			99			103		—
Commercial real estate	1,585			1,592			1,664		—
Residential real estate	1,948			1,961			1,958		2
Consumer	16			17			16		—
Total	$	8,663		$	8,537		$	8,756	$	37
	Accruing TDRs
	December 31, 2014
	Recorded			Average			Unpaid		Unfunded
	investment			year-to-			principal		commitments
				date			balance		to fund
				recorded					TDRs
				investment
Commercial	$	13,249		$	12,496		$	13,249	$	375
Agriculture	2,711			3,110			2,715		—
Commercial real estate	610			627			622		—
Residential real estate	2,687			2,767			2,714		2
Consumer	18			20			18		—
Total	$	19,275		$	19,020		$	19,318	$	377
The following table summarizes the Company’s carrying value of non-accrual TDRs as of March 31, 2015 and December 31, 2014 (in thousands):
	Non - Accruing TDRs
	March 31, 2015						December 31, 2014
	Covered			Non-covered			Covered		Non-covered
Commercial	$	1		$	3,693		$	1	$	3,993
Agriculture	81			154			201		164
Commercial real estate	83			327			94		364
Residential real estate	898			1,029			910		1,056
Consumer	—			185			—		190
Total	$	1,063		$	5,388		$	1,206	$	5,767
Accrual of interest is resumed on loans that were on non-accrual only after the loan has performed sufficiently. The Company had no TDRs that were modified within the past 12 months and had defaulted on their restructured terms during the three months ended March 31, 2015.
During the three months ended March 31, 2014, the Company had two TDRs that had been modified within the past 12 months that defaulted on their restructured terms. The defaulted TDRs were an agriculture loan and a consumer loan totaling $26 thousand. For purposes of this disclosure, the Company considers “default” to mean 90 days or more past due on principal or interest.
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 three months ended March 31, 2015 and 2014 (in thousands):
	March 31,			March 31,
	2015			2014
Accretable yield beginning balance	$	113,463		$	130,624
Reclassification from non-accretable difference	11,186			6,164
Reclassification to non-accretable difference	(1,137		)	(590		)
Accretion	(12,694		)	(16,900		)
Accretable yield ending balance	$	110,818		$	119,298
Below is the composition of the net book value for loans accounted for under ASC 310-30 at March 31, 2015 and December 31, 2014 (in thousands):
	March 31,			December 31,
	2015			2014
Contractual cash flows	$	709,447		$	751,932
Non-accretable difference	(348,775		)	(358,824		)
Accretable yield	(110,818		)	(113,463		)
Loans accounted for under ASC 310-30	$	249,854		$	279,645

Allowance_for_Loan_Losses

Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2015
Receivables [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 months ended March 31, 2015 and 2014 (in thousands):
		Three months ended March 31, 2015
		Commercial			Agriculture			Commercial			Residential			Consumer			Total
								real estate			real estate
	Beginning balance	$	8,598		$	1,009		$	3,819		$	3,771		$	416		$	17,613
	Non 310-30 beginning balance	8,598			541			3,597			3,743			413			16,892
	Charge-offs	(3		)	(47		)	(2		)	(82		)	(208		)	(342		)
	Recoveries	21			—			15			30			83			149
	Provision/recoupment	1,284			57			(82		)	96			48			1,403
	Non 310-30 ending balance	9,900			551			3,528			3,787			336			18,102
	ASC 310-30 beginning balance	—			468			222			28			3			721
	Charge-offs	—			—			—			—			—			—
	Recoveries	—			—			—			—			—			—
	Provision (recoupment)	20			132			(85		)	(28		)	11			50
	ASC 310-30 ending balance	20			600			137			—			14			771
	Ending balance	$	9,920		$	1,151		$	3,665		$	3,787		$	350		$	18,873
	Ending allowance balance attributable to:
	Non 310-30 loans individually evaluated for impairment	$	725		$	2		$	12		$	203		$	2		$	944
	Non 310-30 loans collectively evaluated for impairment	9,175			549			3,516			3,584			334			17,158
	ASC 310-30 loans	20			600			137			—			14			771
	Total ending allowance balance	$	9,920		$	1,151		$	3,665		$	3,787		$	350		$	18,873
	Loans:
	Non 310-30 individually evaluated for impairment	$	17,818		$	495		$	3,964		$	8,390		$	231		$	30,898
	Non 310-30 collectively evaluated for impairment	814,906			113,113			384,869			594,514			28,115			1,935,517
	ASC 310-30 loans	21,481			19,067			171,742			33,158			4,406			249,854
	Total loans	$	854,205		$	132,675		$	560,575		$	636,062		$	32,752		$	2,216,269
		Three months ended March 31, 2014
		Commercial			Agriculture			Commercial			Residential			Consumer			Total
								real estate			real estate
	Beginning balance	$	4,258		$	1,237		$	2,276		$	4,259		$	491		$	12,521
	Non 310-30 beginning balance	4,029			572			1,984			4,165			491			11,241
	Charge-offs	(386		)	—			—			(20		)	(171		)	(577		)
	Recoveries	58			—			37			90			76			261
	Provision (recoupment)	1,880			(24		)	(44		)	(66		)	77			1,823
	Non 310-30 ending balance	5,581			548			1,977			4,169			473			12,748
	ASC 310-30 beginning balance	229			665			292			94			—			1,280
	Charge-offs	(2		)	—			—			—			—			(2		)
	Recoveries	—			—			—			—			—			—
	Provision (recoupment)	(84		)	—			(56		)	(29		)	115			(54		)
	ASC 310-30 ending balance	143			665			236			65			115			1,224
	Ending balance	$	5,724		$	1,213		$	2,213		$	4,234		$	588		$	13,972
	Ending allowance balance attributable to:
	Non 310-30 loans individually evaluated for impairment	$	190		$	1		$	32		$	453		$	3		$	679
	Non 310-30 loans collectively evaluated for impairment	5,391			547			1,945			3,716			470			12,069
	ASC 310-30 loans	143			665			236			65			115			1,224
	Total ending allowance balance	$	5,724		$	1,213		$	2,213		$	4,234		$	588		$	13,972
	Loans:
	Non 310-30 individually evaluated for impairment	$	9,061		$	9,306		$	5,035		$	9,452		$	249		$	33,103
	Non 310-30 collectively evaluated for impairment	521,401			122,280			312,102			539,306			26,854			1,521,943
	ASC 310-30 loans	52,107			23,545			263,608			60,467			6,819			406,546
	Total loans	$	582,569		$	155,131		$	580,745		$	609,225		$	33,922		$	1,961,592
	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 had $0.2 million net charge-offs of non ASC 310-30 loans during the three months ended March 31, 2015. Strong credit quality trends in the non 310-30 loan portfolio continued during the three months ended March 31, 2015, and management's evaluation resulted in a provision for loan losses on the non 310-30 loans of $1.4 million during the three months ended March 31, 2015.
	During the three months ended March 31, 2015, the Company re-estimated the expected cash flows of the loan pools accounted for under ASC 310-30. The re-measurement resulted in net provision of $50 thousand for the three months ended March 31, 2015, which was comprised primarily of provision of $132 thousand in the agriculture segment and recoupment of previous valuation allowances of $85 thousand in the commercial real estate segment, respectively, during the three months ended March 31, 2015.
	The Company charged off $0.3 million, net of recoveries, of non ASC 310-30 loans during the three months ended March 31, 2014, all of which had previously provided specific reserves. Strong credit quality trends in the non 310-30 loan portfolio continued during the three months ended March 31, 2014, and when coupled with origination activity, resulted in a provision for loan losses on the non 310-30 loans of $1.8 million.
	During the three months ended March 31, 2014, the Company remeasured 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 recoupment of previous valuations allowances of $54 thousand for the three months ended March 31, 2014, which was comprised of reversals of previous valuation allowances of $84 thousand, $56 thousand, and $29 thousand in the commercial, commercial real estate and residential real estate segments, respectively, and net impairments of $115 thousand in the consumer segment.

FDIC_Indemnification_Asset

FDIC Indemnification Asset	3 Months Ended
	Mar. 31, 2015
Banking and Thrift [Abstract]
FDIC Indemnification Asset	FDIC Indemnification Asset
	Under the terms of the purchase and assumption agreements 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. Covered assets may be resolved 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 gains or losses realized from the resolution of covered assets reduce or increase, respectively, the amount recoverable from the FDIC. Covered gains or losses that are incurred in excess of the expected reimbursements (which are reflected in the FDIC indemnification asset balance), are recognized in the consolidated statements of operations as FDIC loss sharing income in the period in which they occur.
	Below is a summary of the activity related to the FDIC indemnification asset during the three months ended March 31, 2015 and 2014 (in thousands):
		For the three months ended
		March 31,			March 31,
		2015			2014
	Balance at beginning of period	$	39,082		$	64,447
	Amortization	(7,670		)	(7,608		)
	FDIC portion of (recoveries) charge-offs exceeding fair value marks	(4,900		)	(133		)
	Changes for FDIC loss share submissions	1,342			(29		)
	Balance at end of period	$	27,854		$	56,677
	The $7.7 million of amortization of the FDIC indemnification asset recognized during the three months ended March 31, 2015 resulted from an overall increase in actual and expected cash flows of 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 loan pools as an adjustment to yield. The claims filed with the FDIC 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 three months ended March 31, 2015, the Company paid a net $1.3 million to the FDIC.
	During the three months ended March 31, 2014, the Company recognized $7.6 million of amortization on the FDIC indemnification asset, and further reduced the carrying value of the FDIC indemnification asset by $29 thousand as a result of claims filed and payments received from the FDIC.

Other_Real_Estate_Owned

Other Real Estate Owned	3 Months Ended
	Mar. 31, 2015
Banking and Thrift [Abstract]
Other Real Estate Owned	Other Real Estate Owned
	A summary of the activity in the OREO balances during the three months ended March 31, 2015 and 2014 is as follows (in thousands):
		For the three months ended March 31,
		2015			2014
	Beginning balance	$	29,120		$	70,125
	Transfers from loan portfolio, at fair value	498			236
	Impairments	(470		)	(822		)
	Sales	(7,202		)	(4,143		)
	Gain on sale of OREO, net	1,471			587
	Ending balance	$	23,417		$	65,983
	Of the $23.4 million of OREO at March 31, 2015, $15.9 million, or 67.9%, was covered by loss sharing agreements with the FDIC. At December 31, 2014, $18.5 million, or 63.4%, of the $29.1 million of OREO was covered by loss sharing agreements. Any losses on these assets are substantially offset by a corresponding change in the FDIC indemnification asset.
	At both March 31, 2015 and December 31, 2014, OREO balances excluded $8.1 million 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. The Company maintains a receivable in other assets for these minority interests.

Borrowings

Borrowings	3 Months Ended
	Mar. 31, 2015
Disclosure of Repurchase Agreements [Abstract]
Federal Home Loan Bank Advances, Disclosure [Text Block]	Borrowings
	As a member of the FHLB of Des Moines, the Bank has access to term financing from the FHLB. These borrowings are secured under an advance, pledge and securities agreement, which includes primarily real estate loans. Total advances at both March 31, 2015 and December 31, 2014 were $40.0 million. All of the outstanding advances have fixed interest rates and interest expense related to FHLB advances totaled $164 thousand for the three months ended March 31, 2015. More information about FHLB advances at March 31, 2015 is detailed in the table below (dollars in thousands):
	Maturity Year	March 31, 2015		Rate
	2016	$	15,000	0.84	%
	2018	$	10,000	1.81	%
	2020	$	15,000	2.33	%

Regulatory_Capital

Regulatory Capital	3 Months Ended
	Mar. 31, 2015
Banking and Thrift [Abstract]
Regulatory Capital	Regulatory Capital
	As a bank holding company, the Company is subject to regulatory capital adequacy requirements implemented by the Federal Reserve. In addition, the Office of the Comptroller of the Currency ("OCC") imposes capital adequacy requirements on our subsidiary bank. The federal banking agencies have risk-based capital adequacy regulations intended to provide a measure of capital adequacy that reflects the degree of risk associated with a banking organization’s operations. Under these regulations, assets are assigned to one of several risk categories, and nominal dollar amounts of assets and credit equivalent amounts of off-balance-sheet items are multiplied by a risk adjustment percentage for the category.
	The law requires federal bank regulatory agencies to take “prompt corrective action” with respect to FDIC-insured depository institutions that do not meet minimum capital requirements. A depository institution’s treatment for purposes of the prompt corrective action provisions will depend upon how its capital levels compare to various capital measures and certain other factors, as established by regulation. Under this system, the federal banking regulators have established five capital categories, well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized and critically undercapitalized, in which all institutions are placed. The capital adequacy regulations require banks to maintain a common equity tier 1 capital ratio of 6.5%, a total tier 1 capital ratio of 8.0%, a total capital ratio of 10.0%, and a leverage ratio of 5.0% to be deemed “well capitalized.” Federal banking regulators are required to take various mandatory supervisory actions and are authorized to take other discretionary actions with respect to institutions in the three undercapitalized categories. The severity of the action depends upon the capital category in which the institution is placed. Generally, subject to a narrow exception, the banking regulator must appoint a receiver or conservator for an institution that is critically undercapitalized. Our regulatory capital ratios and those of the Bank are in excess of the levels established for “well-capitalized” institutions.
	In connection with the approval of the de novo charter for the Bank, the Company agreed to maintain capital levels of at least 10.0% tier 1 leverage ratio, 11.0% tier 1 risk-based capital ratio and 12.0% total risk-based capital ratio at our subsidiary bank. In March 2015, the Bank received approval and a waiver from the OCC under the OCC Operating Agreement to permanently reduce the Bank's capital by $50.0 million. As a result, the Bank paid a $50.0 million cash dividend to the Company during the first quarter of 2015.
	At March 31, 2015 and December 31, 2014, the Bank 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):
		March 31, 2015
		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	14.1	%	$	684,742	N/A		N/A		4	%	$	193,916
	NBH Bank, N.A.	11.1	%	536,375		10	%	$	482,858	4	%	193,143
	Common equity tier 1 risk-based capital
	Consolidated	26.3	%	684,742		6.5	%	$	168,947	4.5	%	$	116,963
	NBH Bank, N.A.	20.8	%	536,375		6.5	%	167,683		4.5	%	116,088
	Tier 1 risk-based capital ratio (2)
	Consolidated	26.3	%	$	684,742	8	%	$	207,935	6	%	$	155,951
	NBH Bank, N.A.	20.8	%	536,375		11	%	283,771		6	%	154,784
	Total risk-based capital ratio (2)
	Consolidated	27.1	%	$	703,867	10	%	$	259,919	8	%	$	207,935
	NBH Bank, N.A.	21.5	%	555,499		12	%	309,568		8	%	206,379
		December 31, 2014
		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	15	%	$	712,222	N/A		N/A		4	%	$	190,148
	NBH Bank, N.A.	12.1	%	573,934		10	%	$	473,478	4	%	189,391
	Tier 1 risk-based capital ratio (2)
	Consolidated	28.9	%	$	712,222	6	%	$	147,796	4	%	$	98,530
	NBH Bank, N.A.	23.5	%	573,934		11	%	268,855		4	%	97,766
	Total risk-based capital ratio (2)
	Consolidated	29.6	%	$	730,086	10	%	$	246,326	8	%	$	197,061
	NBH Bank, N.A.	24.2	%	591,799		12	%	293,297		8	%	195,531
	-1	These ratio requirements for NBH Bank, N.A. are reflective of the agreements NBH Bank, N.A. has made with its various regulators in connection with the approval of its de novo charter.
	-2	Due to the conditional guarantee represented by the loss sharing agreements, the FDIC indemnification asset and the portion of assets covered by the FDIC loss sharing agreements are risk-weighted at 20% for purposes of risk-based capital computations.

FDIC_Loss_Sharing_Income

FDIC Loss Sharing Income	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
FDIC Loss Sharing Income	FDIC Loss Sharing (Expense) Income
	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 (expense) income during the three months ended March 31, 2015 and 2014 (in thousands):
		For the three months ended
		March 31, 2015			March 31, 2014
	Clawback liability amortization	$	(368	)	$	(328	)
	Clawback liability remeasurement	(1,107		)	(516		)
	Reimbursement to FDIC for gain on sale of and income from covered OREO	(672		)	(918		)
	Reimbursement to FDIC for recoveries	(8		)	(85		)
	FDIC reimbursement of covered asset resolution costs	1,345			890
	Total	$	(810	)	$	(957	)

Stockbased_Compensation_and_Em

Stock-based Compensation and Employee Benefits	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation and Employee Benefits	Stock-based Compensation and Benefits
	The Company provides stock-based compensation in accordance with shareholder-approved plans. During the second quarter of 2014, shareholders approved the 2014 Omnibus Incentive Plan (the "2014 Plan"). The 2014 Plan replaces the NBH Holdings Corp. 2009 Equity Incentive Plan (the "Prior Plan"), pursuant to which the Company granted equity awards prior to the approval of the 2014 Plan. Pursuant to the 2014 Plan, the Compensation Committee of the Board of Directors has the authority to grant, from time to time, awards of options, stock appreciation rights, restricted stock, restricted stock units, performance units, other stock-based awards, or any combination thereof to eligible persons.
	The aggregate number of Class A common stock available for issuance under the 2014 Plan is 5,134,715 shares. Any shares that are subject to stock options or stock appreciation rights under the 2014 Plan will be counted against the amount available for issuance as one share for every one share granted, and any shares that are subject to awards under the 2014 Plan other than stock options or stock appreciation rights will be counted against the amount available for issuance as 3.25 shares for every one share granted. The 2014 Plan provides for recycling of shares from both the Prior Plan and the 2014 Plan, the terms of which are further described in the Company's Proxy Statement for its 2014 Annual Meeting of Shareholders.
	To date, the Company has issued stock options and restricted stock under the plans. The Compensation Committee sets the option exercise price at the time of grant but in no case is the exercise price less than the fair market value of a share of stock at the date of grant.
	The Company issued stock options and restricted stock in accordance with the plans during the three months ended March 31, 2015. The following table summarizes stock option activity for the three months ended March 31, 2015:
		Options		Weighted		Weighted	Aggregate
				Average		Average	Intrinsic
				Exercise		Remaining	Value
				Price		Contractual
						Term in
						Years
	Outstanding at December 31, 2014	3,597,111		$	19.9	4.46	$	223,211
	Granted	1,187		18.48
	Forfeited	(16,171	)	18.65
	Surrendered	—		—
	Exercised	—		—
	Expired	—		—
	Outstanding at March 31, 2015	3,582,127		$	19.9	4.22	$	83,653
	Options fully vested and exercisable at March 31, 2015	3,320,998		$	19.99	3.88	$	—
	Options expected to vest	254,057		$	18.89	8.21	$	68,271
	Stock option expense is included in salaries and benefits in the accompanying consolidated statements of operations and totaled $0.1 million and $0.3 million for the three months ended March 31, 2015 and 2014, respectively. At March 31, 2015, there was $0.7 million of total unrecognized compensation cost related to non-vested stock options granted under the plans. The cost is expected to be recognized over a weighted average period of 0.9 years.
	Expense related to non-vested restricted stock totaled $0.5 million and $0.4 million during the three months ended March 31, 2015 and 2014, respectively, and is included in salaries and benefits in the Company’s consolidated statements of operations. As of March 31, 2015, there was $1.7 million of total unrecognized compensation cost related to non-vested restricted shares granted under the plans, which is expected to be recognized over a weighted average period of 1.0 years. The following table summarizes restricted stock activity for the three months ended March 31, 2015:
		Total Restricted Shares		Weighted Average Grant-Date Fair Value
	Unvested at December 31, 2014	955,398		$	15.16
	Vested	—		—
	Granted	1,187		18.48
	Forfeited	(2,648	)	18.47
	Surrendered	—		—
	Unvested at March 31, 2015	953,937		$	15.15

Warrants

Warrants	3 Months Ended
	Mar. 31, 2015
Warrants and Rights Note Disclosure [Abstract]
Warrants	Warrants
	At March 31, 2015 and December 31, 2014, the Company had 830,750 issued and outstanding warrants to purchase Company stock. The warrants were granted to certain lead shareholders of the Company, all with an exercise price of $20.00 per share. The term of the warrants is for ten years from the date of grant and the expiration dates of the warrants range from October 20, 2019 to September 30, 2020. The fair value of the warrants was estimated to be $2.9 million and $3.3 million at March 31, 2015 and December 31, 2014, respectively. The fair value of the warrants was estimated using a Black-Scholes option pricing model utilizing the following assumptions at the indicated dates:
		March 31, 2015		December 31, 2014
	Risk-free interest rate	1.35	%	1.67	%
	Expected volatility	24.76	%	24.18	%
	Expected term (years)	5-Apr		6-May
	Dividend yield	1.06	%	1.03	%
	The Company’s shares became publicly traded on September 20, 2012 and prior to that, had limited private trading. Due to the limited historical volatility of the Company's own stock, expected volatility was calculated using a time-based weighted migration of the Company’s own stock price volatility coupled with the median historical volatility, for a period commensurate with the expected term of the warrants, of those of a peer group. The risk-free rate for the expected term of the warrants was based on the U.S. Treasury yield curve and based on the expected term. The expected term was estimated based on the contractual term of the warrants.
	The Company recorded a benefit of $0.4 million and $0.9 million for the three months ended March 31, 2015 and March 31, 2014, respectively, in the consolidated statements of operations resulting from the change in fair value of the warrant liability.

Common_Stock

Common Stock	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Common Stock	Common Stock
	On February 11, 2015, the Board of Directors authorized a new share repurchase program for up to $50.0 million from time to time in either the open market or through privately negotiated transactions. This new program replaced the previous $50.0 million share repurchase program approved during the fourth quarter of 2014. During the three months ended March 31, 2015, the Company repurchased 2,087,166 shares for $37.7 million at a weighted average price of $18.03 per share.
	The Company had 36,412,058 shares of Class A common stock and 385,729 shares of Class B common stock outstanding as of March 31, 2015, and 38,017,179 shares of Class A common stock and 867,774 shares of Class B common stock outstanding as of December 31, 2014. Additionally, as of March 31, 2015 and December 31, 2014, the Company had 953,937 and 955,398 shares, respectively, of restricted Class A common stock issued but not yet vested under the 2014 Plan and the Prior Plan that are not included in shares outstanding until such time that they are vested; however, these shares do have voting and certain dividend rights during the vesting period.

Income_Per_Share

Income Per Share	3 Months Ended
	Mar. 31, 2015
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 non-forfeitable 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 of the unaudited consolidated financial statements.
	The Company had 36,797,787 and 44,486,467 shares outstanding (inclusive of Class A and B) as of March 31, 2015 and 2014, respectively, exclusive of issued non-vested restricted shares. 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 months ended March 31, 2015 and 2014, respectively.
	The following table illustrates the computation of basic and diluted income per share for the three months ended March 31, 2015 and 2014 (in thousands, except share and earnings per share information):
		For the three months ended
		March 31,			March 31,
		2015			2014
	Distributed earnings	$	1,908		$	2,276
	Undistributed earnings (distributions in excess of earnings)	(662		)	(845		)
	Net income	$	1,246		$	1,431
	Less: earnings allocated to participating securities	(10		)	(5		)
	Earnings allocated to common shareholders	$	1,236		$	1,426
	Weighted average shares outstanding for basic earnings per common share	38,028,506			44,819,644
	Dilutive effect of equity awards	106			35,827
	Dilutive effect of warrants	—			7,667
	Weighted average shares outstanding for diluted earnings per common share	38,028,612			44,863,138
	Basic earnings per share	$	0.03		$	0.03
	Diluted earnings per share	$	0.03		$	0.03
	The Company had 3,582,127 and 3,503,403 outstanding stock options to purchase common stock at weighted average exercise prices of $19.90 and $19.92 per share at March 31, 2015 and 2014, 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 March 31, 2015 and 2014. The warrants have an exercise price of $20.00, which was out-of-the-money for purposes of dilution calculations during the three months ended March 31, 2015. The Company had 953,937 and 1,021,127 unvested restricted shares issued as of March 31, 2015 and 2014, respectively, which have performance, market and/or 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	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	Derivatives
	Risk management objective of using derivatives
	The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company has established policies that neither carrying value nor fair value at risk should exceed established guidelines. The Company has designed strategies to confine these risks within the established limits and identify appropriate trade-offs in the financial structure of its balance sheet. These strategies include the use of derivative financial instruments to help achieve the desired balance sheet repricing structure while meeting the desired objectives of its clients. Currently the Company employs certain interest rate swaps that are designated as fair value hedges as well as economic hedges. The Company manages a matched book with respect to its derivative instruments in order to minimize its net risk exposure resulting from such transactions.
	Fair values of derivative instrument of the balance sheet
	The table below presents the fair value of the Company’s derivative financial instruments as well as their classification on the Consolidated Statements of Financial Condition as of March 31, 2015 and December 31, 2014 (dollars in thousands).
	Information about the valuation methods used to measure fair value is provided in note 17 of the unaudited consolidated financial statements.
				Asset Derivatives							Liability Derivatives
				Fair Value							Fair Value
		Balance Sheet Location		March 31, 2015			December 31, 2014			Balance Sheet Location	March 31, 2015		December 31, 2014
	Derivatives designated as hedging instruments
	Interest rate products	Other assets		$	38		$	10		Other liabilities	$	5,386	$	3,206
	Total derivatives designated as hedging instruments			$	38		$	10			$	5,386	$	3,206
	Derivatives not designated as hedging instruments
	Interest rate products	Other assets		$	2,018		$	1,418		Other liabilities	$	2,164	$	1,522
	Total derivatives not designated as hedging instruments			$	2,018		$	1,418			$	2,164	$	1,522
	Fair value hedges of interest rate risk
	Interest rate swaps designated as fair value hedges involve the receipt of variable-rate amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without the exchange of the underlying notional amount. As of March 31, 2015, the Company had 16 interest rate swaps with a notional amount of $131.4 million that were designated as fair value hedges of interest rate risk associated with the Company’s fixed-rate loans. The Company had 11 outstanding interest rate swaps with a notional amount of $68.8 million that were designated as a fair value hedge as of December 31, 2014.
	For qualifying derivatives designated as fair value hedges, the gain or loss on the derivative, as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in earnings. The Company includes the gain or loss on the hedged items in the same line item as the offsetting loss or gain on the related derivatives. During the three months ended March 31, 2015, the Company recognized a net loss of $140 thousand, respectively, in non-interest expense related to hedge ineffectiveness. During the three months ended March 31, 2014, the Company recognized a net loss of $73 thousand in non-interest expense related to hedge ineffectiveness.
	Non-designated hedges
	Derivatives not designated as hedges are not speculative and consist of interest rate swaps with commercial banking clients that facilitate their respective risk management strategies. Those interest rate swaps are simultaneously hedged by offsetting interest rate swaps that the Company executes with a third party, such that the Company minimizes its net risk exposure resulting from such transactions. As the interest rate swaps associated with this program do not meet the strict hedge accounting requirements, changes in the fair value of both the client swaps and the offsetting swaps are recognized directly in earnings. As of March 31, 2015, the Company had 13 matched interest rate swap transactions with an aggregate notional amount of $42.7 million related to this program. As of December 31, 2014, the Company had 11 matched interest rate swap transactions with an aggregate notional amount of $35.9 million related to this program.
	Effect of Derivative Instruments on the Consolidated Statement of Operations
	The tables below present the effect of the Company’s derivative financial instruments on the consolidated statement of operations for the three months ended March 31, 2015 and 2014 (in thousands).
	Derivatives in fair value hedging relationships		Location of loss recognized in income on derivatives	Amount of loss recognized in income on derivatives
				For the three months ended March 31,
				2015			2014
	Interest rate products		Interest income	$	(2,152	)	$	(614	)
	Total			$	(2,152	)	$	(614	)
	Derivatives in fair value hedging relationships		Location of gain recognized in income on derivatives	Amount of gain recognized in income on hedged items
				For the three months ended March 31,
				2015			2014
	Interest rate products		Interest income	$	2,013		$	541
	Total			$	2,013		$	541
				Amount of loss recognized in income on derivatives
				For the three months ended March 31,
	Derivatives not designated as hedging instruments		Location of loss recognized in income on derivatives	2015			2014
	Interest rate products		Other non-interest income	$	(39	)	(14	)
	Total			$	(39	)	(14	)
	Credit-risk-related Contingent Features
	The Company has agreements with its derivative counterparties that contain a provision where if the Company defaults on any of its indebtedness for reasons other than an error or omission of an administrative or operational nature, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations.
	The Company also has agreements with certain of its derivative counterparties that contain a provision where if the Company fails to maintain its status as a well/adequately capitalized institution, then the counterparty has the right to terminate the derivative positions and the Company would be required to settle its obligations under the agreements.
	As of March 31, 2015, the termination value of derivatives in a net liability position related to these agreements was $8.2 million, which includes accrued interest but excludes any adjustment for nonperformance risk. The Company has minimum collateral posting thresholds with certain of its derivative counterparties and as of March 31, 2015, the Company had posted $9.2 million in eligible collateral.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	In the normal course of business, the Company enters into various off-balance sheet commitments to help meet the financing needs of clients. These financial instruments include commitments to extend credit, commercial and consumer lines of credit and standby letters of credit. The same credit policies are applied to these commitments as the loans on the consolidated statements of financial condition; however, these commitments involve varying degrees of credit risk in excess of the amount recognized in the consolidated statements of financial condition. At March 31, 2015 and December 31, 2014, the Company had loan commitments totaling $468.6 million and $485.5 million, respectively, and standby letters of credit that totaled $10.4 million and $10.0 million, respectively. The total amounts of unused commitments do not necessarily represent future credit exposure or cash requirements, as commitments often expire without being drawn upon. However, the contractual amount of these commitments, offset by any additional collateral pledged, represents the Company’s potential credit loss exposure. Amounts funded under non-cancelable commitments in effect at the date of acquisition are covered under the applicable loss sharing agreements if certain conditions are met.
	Total unfunded commitments at March 31, 2015 and December 31, 2014 were as follows (in thousands):
		March 31, 2015						December 31, 2014
		Covered		Non-covered		Total		Covered		Non-covered		Total
	Commitments to fund loans
	Residential	$	—	$	2,669	$	2,669	$	—	$	1,683	$	1,683
	Commercial and commercial real estate	11		191,008		191,019		11		202,593		202,604
	Construction and land development	—		27,079		27,079		—		35,814		35,814
	Consumer	—		4,412		4,412		—		4,376		4,376
	Credit card lines of credit	—		17,717		17,717		—		18,065		18,065
	Unfunded commitments under lines of credit	5,581		220,107		225,688		7,645		215,305		222,950
	Commercial and standby letters of credit	234		10,140		10,374		234		9,731		9,965
	Total	$	5,826	$	473,132	$	478,958	$	7,890	$	487,567	$	495,457
	Commitments to fund loans—Commitments to fund loans are legally binding agreements to lend to clients in accordance with predetermined contractual provisions providing there have been no violations of any conditions specified in the contract. These commitments are generally at variable interest rates and are for specific periods or contain termination clauses and may require the payment of a fee. The total amounts of unused commitments are not necessarily representative of future credit exposure or cash requirements, as commitments often expire without being drawn upon.
	Credit card lines of credit—The Company extends lines of credit to clients through the use of credit cards issued by the Bank. These lines of credit represent the maximum amounts allowed to be funded, many of which will not exhaust the established limits, and as such, these amounts are not necessarily representations of future cash requirements or credit exposure.
	Unfunded commitments under lines of credit—In the ordinary course of business, the Company extends revolving credit to its clients. These arrangements may require the payment of a fee.
	Commercial and standby letters of credit—As a provider of financial services, the Company routinely issues commercial and standby letters of credit, which may be financial standby letters of credit or performance standby letters of credit. These are various forms of “back-up” commitments to guarantee the performance of a client to a third party. While these arrangements represent a potential cash outlay for the Company, the majority of these letters of credit will expire without being drawn upon. Letters of credit are subject to the same underwriting and credit approval process as traditional loans, and as such, many of them have various forms of collateral securing the commitment, which may include real estate, personal property, receivables or marketable securities.
	Contingencies
	In the ordinary course of business, the Company and the Bank may be subject to litigation. Based upon the available information and advice from the Company’s legal counsel, management does not believe that any potential, threatened or pending litigation to which it is a party will have a material adverse effect on the Company’s liquidity, financial condition or results of operations.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
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 three months ended March 31, 2015 and 2014, 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 March 31, 2015 and December 31, 2014, the Company did not hold any level 1 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 March 31, 2015 and December 31, 2014, the Company’s level 2 securities included 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.
	Derivatives—The Company's derivative instruments are limited to interest rate swaps that may be accounted for as fair value hedges or non-designated hedges. The fair values of the swaps incorporate credit valuation adjustments in order to appropriately reflect nonperformance risk in the fair value measurements. The credit valuation adjustment is the dollar amount of the fair value adjustment related to credit risk and utilizes a probability weighted calculation to quantify the potential loss over the life of the trade. The credit valuation adjustments are calculated by determining the total expected exposure of the derivatives (which incorporates both the current and potential future exposure) and then applying the respective counterparties’ credit spreads to the exposure offset by marketable collateral posted, if any. Certain derrivative transactions are executed with counterparties who are large financial institutions ("dealers"). International Swaps and Derivative Association Master Agreements ("ISDA") and Credit Support Annexes ("CSA") are employed for all contracts with dealers. These contracts contain bilateral collateral arrangements. The fair value inputs of these financial instruments are determined using discounted cash flow analysis through the use of third-party models whose significant inputs are readily observable market parameters, primarily yield curves, with appropriate adjustments for liquidity and credit risk, and are classified as level 2.
	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 using a time-based weighted migration of the Company’s own stock price volatility coupled with the median historical volatility, for a period commensurate with the expected term of the warrants, of those eight comparable companies with publicly traded shares, and is deemed a significant unobservable input to the valuation model, as such these instruments are classified as level 3.
	Clawback liability—The Company periodically measures the net present value of expected future cash payments 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, as such these instruments are classified as level 3.
	The tables below present the financial instruments measured at fair value on a recurring basis as of March 31, 2015 and December 31, 2014 on the consolidated statements of financial condition utilizing the hierarchy structure described above (in thousands):
		March 31, 2015
		Level 1			Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	—		$	385,236		$	—	$	385,236
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—			1,027,759			—		1,027,759
	Other securities	—			—			419		419
	Derivatives	—			2,056			—		2,056
	Total assets at fair value	$	—		$	1,415,051		$	419	$	1,415,470
	Liabilities:
	Warrant liability	$	—		$	—		$	2,938	$	2,938
	Clawback liability	—			—			37,813		37,813
	Derivatives	—			7,550			—		7,550
	Total liabilities at fair value	$	—		$	7,550		$	40,751	$	48,301
		December 31, 2014
		Level 1			Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	—		$	404,215		$	—	$	404,215
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—			1,074,580			—		1,074,580
	Other securities	—			—			419		419
	Derivatives	—			1,428			—		1,428
	Total assets at fair value	$	—		$	1,480,223		$	419	$	1,480,642
	Liabilities:
	Warrant liability	$	—		$	—		$	3,328	$	3,328
	Clawback liability	—			—			36,338		36,338
	Derivatives	—			4,728			—		4,728
	Total liabilities at fair value	$	—		$	4,728		$	39,666	$	44,394
	The table below details the changes in level 3 financial instruments during the three months ended March 31, 2015 and March 31, 2014 (in thousands):
		Warrant			Clawback
		liability			liability
	Balance at December 31, 2013	$	6,281		$	32,465
	Change in value	(898		)	516
	Amortization	—			328
	Net change in level 3	$	(898	)	$	844
	Balance at March 31, 2014	$	5,383		$	33,309
	Balance at December 31, 2014	$	3,328		$	36,338
	Change in value	(390		)	1,107
	Amortization	—			368
	Net change in Level 3	(390		)	1,475
	Balance at March 31, 2015	$	2,938		$	37,813
	Fair Value 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 three months ended March 31, 2015, the Company measured eight loans not accounted for under ASC 310-30 at fair value on a non-recurring basis. These loans carried specific reserves totaling $0.9 million at March 31, 2015. During the three months ended March 31, 2015, the Company added specific reserves of $0.7 million for four loans with carrying balances of $1.0 million at March 31, 2015. The Company also decreased specific reserves of $0.1 million for four loans during the three months ended March 31, 2015, primarily due to updated appraisals.
	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 fair value of the collateral less estimated selling costs. The estimated fair values of OREO are updated periodically and further valuation adjustments may be taken to reflect a new basis. The Company recognized $0.5 million of OREO impairments in its consolidated statements of operations during the three months ended March 31, 2015, of which $0.2 million, or 44.5%, were on OREO that was covered by loss sharing agreements with the FDIC. During the three months ended March 31, 2014, the Company recognized $0.8 million of OREO impairments in its consolidated statements of operations, of which $0.6 million, or 69.6%, 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 three months ended March 31, 2015 and 2014 (in thousands):
		March 31, 2015
	Total			Losses from fair value changes
Other real estate owned	$	23,417		$	470
Impaired loans	30,898			146
	31-Mar-14
	Total			Losses from fair value changes
Other real estate owned	$	65,983		$	822
Impaired loans	33,103			465
The Company did not record any liabilities for which the fair value was made on a non-recurring basis during the three months ended March 31, 2015.
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 March 31, 2015. 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
	March 31,						Measures
	2015
Other securities	$	419		Cash investment in private equity fund		Realizable value
Impaired loans	30,898			Appraised value		Appraised values
						Discount rate	0-25%
Clawback liability	37,813			Contractually defined discounted cash flows		Intrinsic loss estimates	$323.3 million -
							$405 million
						Expected credit losses	—
						Discount rate	4%
Warrant liability	2,938			Black-Scholes		Volatility	18%-30%

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2015
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 March 31, 2015 and December 31, 2014, including methods and assumptions utilized for determining fair value of financial instruments, are set forth below (in thousands):
			31-Mar-15				31-Dec-14
		Level in fair	Carrying		Estimated		Carrying		Estimated
		value	amount		fair value		amount		fair value
		measurement
		hierarchy
	ASSETS:
	Cash and cash equivalents	Level 1	$	490,104	$	490,104	$	256,979	$	256,979
	Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	385,236		385,236		404,215		404,215
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	1,027,759		1,027,759		1,074,580		1,074,580
	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	400,408		408,251		422,622		428,323
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	Level 2	103,202		102,552		107,968		106,314
	Capital stock of FHLB	Level 2	7,361		7,361		7,595		7,595
	Capital stock of FRB	Level 2	19,689		19,689		19,450		19,450
	Loans receivable, net	Level 3	2,197,396		2,255,644		2,144,796		2,193,222
	Loans held-for-sale	Level 2	4,935		4,935		5,146		5,146
	Accrued interest receivable	Level 2	12,070		12,070		11,465		11,465
	Derivatives	Level 2	2,056		2,056		1,428		1,428
	LIABILITIES:
	Deposit transaction accounts	Level 2	2,507,801		2,507,801		2,409,137		2,409,137
	Time deposits	Level 2	1,324,661		1,325,585		1,357,051		1,357,885
	Securities sold under agreements to repurchase	Level 2	284,161		284,161		133,552		133,552
	Federal Home Loan Bank advances	Level 2	40,000		40,790		40,000		40,465
	Due to FDIC	Level 3	37,813		37,813		42,011		42,011
	Warrant liability	Level 3	2,938		2,938		3,328		3,328
	Accrued interest payable	Level 2	3,804		3,804		3,608		3,608
	Derivatives	Level 2	7,550		7,550		4,728		4,728
	Cash and cash equivalents
	Cash and cash equivalents have a short-term nature and the estimated fair value is equal to the carrying value.
	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 current market rates offered by the Company, at the respective measurement dates, for deposits of similar remaining maturities.
	Derivative assets and liabilities
	Fair values for derivative assets and liabilities are fully described in note 17 of the unaudited consolidated financial statements.
	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 12 of the unaudited 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.

Recent_Accounting_Pronouncemen1

Recent Accounting Pronouncements - (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans Upon Foreclosure [Policy Text Block]	Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure - In January 2014, the FASB issued Accounting Standards Update ("ASU") 2014-04, “Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure.” This update amends ASC Topic 310-40 and clarifies that an “in substance repossession or foreclosure” has occurred upon the creditor obtaining either legal title to the property upon completion of foreclosure, or the borrower conveying all interest in the property through completion of a deed in lieu of foreclosure. Upon occurrence, the creditor derecognizes the loan receivable and recognizes the collateralized real estate property. The amendments in the ASU became effective for the Company for interim and annual periods beginning after December 15, 2014. Early adoption was permitted. Adoption of this amendment can be made using either a modified retrospective transition method or a prospective transition method. The adoption of this standard did not have a material impact on the Company’s consolidated financial statements, results of operations or liquidity.
Revenue from Contracts with Customers [Policy Text Block]	Revenue from Contracts with Customers - In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers." This update supersedes revenue recognition requirements in Topic 605, Revenue Recognition, including most industry-specific revenue recognition guidance in the FASB Accounting Standards Codification. The new guidance stipulates that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance provides specific steps that entities should apply in order to achieve this principle. The amendments are effective for interim and annual periods beginning January 1, 2017 and must be applied retrospectively. The Company is in the process of evaluating the impact of the ASU's adoption on the Company's consolidated financial statements.

Investment_Securities_Tables

Investment Securities - (Tables)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities	Available-for-sale investment securities are summarized as follows as of the dates indicated (in thousands):
		March 31, 2015
		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	$	373,802	$	11,434		$	—		$	385,236
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	1,033,190		7,972			(13,403		)	1,027,759
	Other securities	419		—			—			419
	Total	$	1,407,411	$	19,406		$	(13,403	)	$	1,413,414
		December 31, 2014
		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	$	395,244	$	9,014		$	(43	)	$	404,215
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	1,088,834		7,464			(21,718		)	1,074,580
	Other securities	419		—			—			419
	Total	$	1,484,497	$	16,478		$	(21,761	)	$	1,479,214
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):
		March 31, 2015
		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	$	—	$	—		$	—		$	—		$	—	$	—
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	75,887		(1,305		)	611,431			(12,098		)	687,318		(13,403		)
	Total	$	75,887	$	(1,305	)	$	611,431		$	(12,098	)	$	687,318	$	(13,403	)
		December 31, 2014
		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	$	—		$	89,749		$	(43	)	$	89,766	$	(43	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	88,854		(2,053		)	667,368			(19,665		)	756,222		(21,718		)
	Total	$	88,871	$	(2,053	)	$	757,117		$	(19,708	)	$	845,988	$	(21,761	)
Held-to-maturity Securities	Held-to-maturity investment securities are summarized as follows as of the dates indicated (in thousands):
		March 31, 2015
		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	$	400,408	$	7,860		$	(17	)	$	408,251
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	103,202		499			(1,149		)	102,552
	Total investment securities held-to-maturity	$	503,610	$	8,359		$	(1,166	)	$	510,803
		December 31, 2014
		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	$	422,622	$	5,773		$	(72	)	$	428,323
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	107,968		217			(1,871		)	106,314
	Total investment securities held-to-maturity	$	530,590	$	5,990		$	(1,943	)	$	534,637
Held-to-maturity securities continuous unrealized loss position fair value [Table Text Block]	The table below summarizes the unrealized losses as of the dates shown, along with the length of the impairment period (in thousands):
		March 31, 2015
		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	$	—	$	—		$	2,120		$	(17	)	$	2,120	$	(17	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		—			52,949			(1,149		)	52,949		(1,149		)
	Total	$	—	$	—		$	55,069		$	(1,166	)	$	55,069	$	(1,166	)
		December 31, 2014
		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	$	—	$	—		$	35,139		$	(72	)	$	35,139	$	(72	)
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—		—			75,139			(1,871		)	75,139		(1,871		)
	Total	$	—	$	—		$	110,278		$	(1,943	)	$	110,278	$	(1,943	)

Loans_Tables

Loans - (Tables)	3 Months Ended
	Mar. 31, 2015
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 $9.5 million and $10.5 million as of March 31, 2015 and December 31, 2014, respectively (in thousands):
		March 31, 2015
		ASC 310-30			Non 310-30			Total loans		% of total
		loans			loans
	Commercial	$	21,481		$	832,724		$	854,205	38.5	%
	Agriculture	19,067			113,608			132,675		6	%
	Commercial real estate	171,742			388,833			560,575		25.3	%
	Residential real estate	33,158			602,904			636,062		28.7	%
	Consumer	4,406			28,346			32,752		1.5	%
	Total	$	249,854		$	1,966,415		$	2,216,269	100	%
	Covered	$	142,345		$	29,542		$	171,887	7.8	%
	Non-covered	107,509			1,936,873			2,044,382		92.2	%
	Total	$	249,854		$	1,966,415		$	2,216,269	100	%
		December 31, 2014
		ASC 310-30			Non 310-30			Total loans		% of total
		loans			loans
	Commercial	$	22,956		$	772,440		$	795,396	36.8	%
	Agriculture	19,063			118,468			137,531		6.4	%
	Commercial real estate	192,330			369,264			561,594		26	%
	Residential real estate	40,761			591,939			632,700		29.2	%
	Consumer	4,535			30,653			35,188		1.6	%
	Total	$	279,645		$	1,882,764		$	2,162,409	100	%
	Covered	$	160,876		$	32,821		$	193,697	9	%
	Non-covered	118,769			1,849,943			1,968,712		91	%
	Total	$	279,645		$	1,882,764		$	2,162,409	100	%
Past Due Financing Receivables	Loan delinquency for all loans is shown in the following tables at March 31, 2015 and December 31, 2014, respectively (in thousands):
		Total Loans March 31, 2015
		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	$	306		$	71		$	1,142	$	1,519	$	831,205	$	832,724	$	81		$	4,803
	Agriculture	—			36			33		69		113,539		113,608		—			396
	Commercial real estate
	Construction	—			—			—		—		6,718		6,718		—			—
	Acquisition/development	—			—			—		—		4,098		4,098		—			—
	Multifamily	—			—			—		—		17,324		17,324		(1		)	—
	Owner-occupied	57			146			116		319		132,873		133,192		—			778
	Non owner-occupied	105			51			220		376		227,125		227,501		—			220
	Total commercial real estate	162			197			336		695		388,138		388,833		(1		)	998
	Residential real estate
	Senior lien	363			85			653		1,101		550,056		551,157		—			4,438
	Junior lien	24			18			180		222		51,525		51,747		88			509
	Total residential real estate	387			103			833		1,323		601,581		602,904		88			4,947
	Consumer	196			1			189		386		27,960		28,346		6			214
	Total loans excluded from ASC 310-30	$	1,051		$	408		$	2,533	$	3,992	$	1,962,423	$	1,966,415	$	174		$	11,358
	Covered loans excluded from ASC 310-30	$	—		$	48		$	227	$	275	$	29,267	$	29,542	$	75		$	1,154
	Non-covered loans excluded from ASC 310-30	1,051			360			2,306		3,717		1,933,156		1,936,873		99			10,204
	Total loans excluded from ASC 310-30	$	1,051		$	408		$	2,533	$	3,992	$	1,962,423	$	1,966,415	$	174		$	11,358
	Loans accounted for under ASC 310-30
	Commercial	$	275		$	—		$	1,771	$	2,046	$	19,435	$	21,481	$	1,771		$	—
	Agriculture	21			—			380		401		18,666		19,067		379			—
	Commercial real estate	157			170			22,263		22,590		149,152		171,742		22,263			—
	Residential real estate	684			254			335		1,273		31,885		33,158		335			—
	Consumer	173			4			49		226		4,180		4,406		49			—
	Total loans accounted for under ASC 310-30	$	1,310		$	428		$	24,798	$	26,536	$	223,318	$	249,854	$	24,797		$	—
	Covered loans accounted for under ASC 310-30	$	391		$	44		$	22,276	$	22,711	$	119,634	$	142,345	$	22,276		$	—
	Non-covered loans accounted for under ASC 310-30	919			384			2,522		3,825		103,684		107,509		2,521			—
	Total loans accounted for under ASC 310-30	$	1,310		$	428		$	24,798	$	26,536	$	223,318	$	249,854	$	24,797		$	—
	Total loans	$	2,361		$	836		$	27,331	$	30,528	$	2,185,741	$	2,216,269	$	24,971		$	11,358
	Covered loans	$	391		$	92		$	22,503	$	22,986	$	148,901	$	171,887	$	22,351		$	1,154
	Non-covered loans	1,970			744			4,828		7,542		2,036,840		2,044,382		2,620			10,204
	Total loans	$	2,361		$	836		$	27,331	$	30,528	$	2,185,741	$	2,216,269	$	24,971		$	11,358
		Total Loans December 31, 2014
		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	$	83		$	97		$	318	$	498	$	771,942	$	772,440	$	215		$	4,215
	Agriculture	47			—			10		57		118,411		118,468		10			495
	Commercial real estate
	Construction	—			—			—		—		11,748		11,748		—			—
	Acquisition/development	41			—			—		41		4,532		4,573		—			—
	Multifamily	—			—			—		—		10,856		10,856		(1		)	—
	Owner-occupied	336			78			101		515		119,710		120,225		—			843
	Non owner-occupied	158			—			222		380		221,482		221,862		—			222
	Total commercial real estate	535			78			323		936		368,328		369,264		(1		)	1,065
	Residential real estate
	Senior lien	378			1,403			732		2,513		537,022		539,535		—			4,335
	Junior lien	133			1			101		235		52,169		52,404		—			476
	Total residential real estate	511			1,404			833		2,748		589,191		591,939		—			4,811
	Consumer	266			21			39		326		30,327		30,653		39			227
	Total loans excluded from ASC 310-30	$	1,442		$	1,600		$	1,523	$	4,565	$	1,878,199	$	1,882,764	$	263		$	10,813
	Covered loans excluded from ASC 310-30	$	17		$	1,016		$	152	$	1,185	$	31,636	$	32,821	$	75		$	1,317
	Non-covered loans excluded from ASC 310-30	1,425			584			1,371		3,380		1,846,563		1,849,943		188			9,496
Total loans excluded from ASC 310-30	$	1,442		$	1,600		$	1,523	$	4,565	$	1,878,199	$	1,882,764	$	263		$	10,813
Loans accounted for under ASC 310-30
Commercial	$	152		$	—		$	1,755	$	1,907	$	21,049	$	22,956	$	1,754		$	—
Agriculture	—			—			367		367		18,696		19,063		367			—
Commercial real estate	564			92			31,013		31,669		160,661		192,330		31,013			—
Residential real estate	2,014			3,826			646		6,486		34,275		40,761		646			—
Consumer	369			—			54		423		4,112		4,535		54			—
Total loans accounted for under ASC 310-30	$	3,099		$	3,918		$	33,835	$	40,852	$	238,793	$	279,645	$	33,834		$	—
Covered loans accounted for under ASC 310-30	$	576		$	3,892		$	31,239	$	35,707	$	125,169	$	160,876	$	31,238		$	—
Non-covered loans accounted for under ASC 310-30	2,523			26			2,596		5,145		113,624		118,769		2,596			—
Total loans accounted for under ASC 310-30	$	3,099		$	3,918		$	33,835	$	40,852	$	238,793	$	279,645	$	33,834		$	—
Total loans	$	4,541		$	5,518		$	35,358	$	45,417	$	2,116,992	$	2,162,409	$	34,097		$	10,813
Covered loans	$	593		$	4,908		$	31,391	$	36,892	$	156,805	$	193,697	$	31,313		$	1,317
Non-covered loans	3,948			610			3,967		8,525		1,960,187		1,968,712		2,784			9,496
Total loans	$	4,541		$	5,518		$	35,358	$	45,417	$	2,116,992	$	2,162,409	$	34,097		$	10,813
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 March 31, 2015 and December 31, 2014, respectively (in thousands):
		Total Loans March 31, 2015
		Pass			Special			Substandard		Doubtful		Total
					mention
	Loans excluded from ASC 310-30
	Commercial	$	791,459		$	22,549		$	17,992	$	724	$	832,724
	Agriculture	111,118			1,599			891		—		113,608
	Commercial real estate
	Construction	6,718			—			—		—		6,718
	Acquisition/development	4,098			—			—		—		4,098
	Multifamily	17,324			—			—		—		17,324
	Owner-occupied	128,289			154			4,749		—		133,192
	Non owner-occupied	206,603			17,408			3,483		7		227,501
	Total commercial real estate	363,032			17,562			8,232		7		388,833
	Residential real estate
	Senior lien	545,049			—			5,951		157		551,157
	Junior lien	50,435			—			1,298		14		51,747
	Total residential real estate	595,484			—			7,249		171		602,904
	Consumer	28,131			—			215		—		28,346
	Total loans excluded from ASC 310-30	$	1,889,224		$	41,710		$	34,579	$	902	$	1,966,415
	Covered loans excluded from ASC 310-30	$	18,097		$	167		$	11,180	$	98	$	29,542
	Non-covered loans excluded from ASC 310-30	1,871,127			41,543			23,399		804		1,936,873
	Total loans excluded from ASC 310-30	$	1,889,224		$	41,710		$	34,579	$	902	$	1,966,415
	Loans accounted for under ASC 310-30
	Commercial	$	10,148		$	217		$	10,555	$	561	$	21,481
	Agriculture	16,827			31			2,209		—		19,067
	Commercial real estate	77,116			3,629			87,228		3,769		171,742
	Residential real estate	24,415			1,258			7,485		—		33,158
	Consumer	3,599			100			707		—		4,406
	Total loans accounted for under ASC 310-30	$	132,105		$	5,235		$	108,184	$	4,330	$	249,854
	Covered loans accounted for under ASC 310-30	$	47,426		$	2,912		$	87,677	$	4,330	$	142,345
	Non-covered loans accounted for under ASC 310-30	84,679			2,323			20,507		—		107,509
	Total loans accounted for under ASC 310-30	$	132,105		$	5,235		$	108,184	$	4,330	$	249,854
	Total loans	$	2,021,329		$	46,945		$	142,763	$	5,232	$	2,216,269
	Total covered	$	65,523		$	3,079		$	98,857	$	4,428	$	171,887
	Total non-covered	1,955,806			43,866			43,906		804		2,044,382
	Total loans	$	2,021,329		$	46,945		$	142,763	$	5,232	$	2,216,269
		Total Loans December 31, 2014
		Pass			Special			Substandard		Doubtful		Total
					mention
	Loans excluded from ASC 310-30
	Commercial	$	742,944		$	10,166		$	19,250	$	80	$	772,440
	Agriculture	114,642			85			3,741		—		118,468
	Commercial real estate
	Construction	11,748			—			—		—		11,748
	Acquisition/development	4,573			—			—		—		4,573
	Multifamily	10,856			—			—		—		10,856
	Owner-occupied	115,178			158			4,889		—		120,225
	Non owner-occupied	199,817			17,607			4,430		8		221,862
	Total commercial real estate	342,172			17,765			9,319		8		369,264
	Residential real estate
	Senior lien	533,630			23			5,744		138		539,535
	Junior lien	51,059			—			1,345		—		52,404
	Total residential real estate	584,689			23			7,089		138		591,939
	Consumer	30,426			—			227		—		30,653
	Total loans excluded from ASC 310-30	$	1,814,873		$	28,039		$	39,626	$	226	$	1,882,764
	Covered loans excluded from ASC 310-30	$	21,240		$	171		$	11,301	$	109	$	32,821
	Non-covered loans excluded from ASC 310-30	1,793,633			27,868			28,325		117		1,849,943
	Total loans excluded from ASC 310-30	$	1,814,873		$	28,039		$	39,626	$	226	$	1,882,764
	Loans accounted for under ASC 310-30
	Commercial	$	11,038		$	282		$	11,092	$	544	$	22,956
	Agriculture	16,854			30			2,179		—		19,063
	Commercial real estate	82,603			3,770			101,966		3,991		192,330
	Residential real estate	29,069			1,403			10,289		—		40,761
Consumer	3,641			105			789		—		4,535
Total loans accounted for under ASC 310-30	$	143,205		$	5,590		$	126,315	$	4,535	$	279,645
Covered loans accounted for under ASC 310-30	$	49,856		$	3,036		$	103,451	$	4,533	$	160,876
Non-covered loans accounted for under ASC 310-30	93,349			2,554			22,864		2		118,769
Total loans accounted for under ASC 310-30	$	143,205		$	5,590		$	126,315	$	4,535	$	279,645
Total loans	$	1,958,078		$	33,629		$	165,941	$	4,761	$	2,162,409
Total covered	$	71,096		$	3,207		$	114,752	$	4,642	$	193,697
Total non-covered	1,886,982			30,422			51,189		119		1,968,712
Total loans	$	1,958,078		$	33,629		$	165,941	$	4,761	$	2,162,409
Schedule Of Impaired Financing Receivable With And Without Related Allowance	Additional information regarding impaired loans at March 31, 2015 and December 31, 2014 is set forth in the table below (in thousands):
		Impaired Loans
		March 31, 2015								December 31, 2014
		Unpaid			Recorded			Allowance		Unpaid		Recorded		Allowance
		principal			investment			for loan		principal		investment		for loan
		balance						losses		balance				losses
								allocated						allocated
	With no related allowance recorded:
	Commercial	$	16,485		$	16,290		$	—	$	16,953	$	16,771	$	—
	Agriculture	—			—			—		3,065		3,061		—
	Commercial real estate
	Construction	—			—			—		—		—		—
	Acquisition/development	—			—			—		—		—		—
	Multifamily	—			—			—		—		—		—
	Owner-occupied	2,188			1,923			—		1,164		970		—
	Non-owner occupied	—			—			—		—		—		—
	Total commercial real estate	2,188			1,923			—		1,164		970		—
	Residential real estate
	Senior lien	354			316			—		694		248		—
	Junior lien	—			—			—		—		—		—
	Total residential real estate	354			316			—		694		248		—
	Consumer	—			—			—		—		—		—
	Total impaired loans with no related allowance recorded	$	19,027		$	18,529		$	—	$	21,876	$	21,050	$	—
	With a related allowance recorded:
	Commercial	$	1,720		$	1,528		$	725	$	894	$	693	$	82
	Agriculture	555			495			2		177		145		—
	Commercial real estate
	Construction	—			—			—		—		—		—
	Acquisition/development	—			—			—		—		—		—
	Multifamily	40			39			—		—		—		—
	Owner-occupied	1,275			965			3		1,321		1,024		5
	Non-owner occupied	1,120			1,037			8		1,140		1,060		9
	Total commercial real estate	2,435			2,041			11		2,461		2,084		14
	Residential real estate
	Senior lien	7,508			6,547			180		7,360		6,359		172
	Junior lien	1,785			1,527			22		1,768		1,515		9
	Total residential real estate	9,293			8,074			202		9,128		7,874		181
	Consumer	268			231			2		277		245		2
	Total impaired loans with a related allowance recorded	$	14,271		$	12,369		$	942	$	12,937	$	11,041	$	279
	Total impaired loans	$	33,298		$	30,898		$	942	$	34,813	$	32,091	$	279
Schedule of Impaired Financing Receivable, Average Recorded Investment and Interest Income Recognized	The table below shows additional information regarding the average recorded investment and interest income recognized on impaired loans for the periods presented (in thousands):
		For the three months ended
		31-Mar-15						31-Mar-14
		Average recorded investment			Interest income recognized			Average recorded investment		Interest income recognized
	With no related allowance recorded:
	Commercial	$	16,252		$	176		$	7,562	$	94
	Agriculture	—			—			9,132		119
	Commercial real estate
	Construction	—			—			—		—
	Acquisition/development	—			—			398		5
	Multifamily	—			—			908		—
	Owner-occupied	1,935			25			1,622		26
	Non owner-occupied	—			—			480		8
	Total commercial real estate	1,935			25			3,408		39
	Residential real estate
	Senior lien	319			—			701		4
	Junior lien	—			—			—		—
	Total residential real estate	319			—			701		4
	Consumer	—			—			—		—
	Total impaired loans with no related allowance recorded	$	18,506		$	201		$	20,803	$	256
	With a related allowance recorded:
	Commercial	$	1,544		$	—		$	2,113	$	12
	Agriculture	583			—			177		—
	Commercial real estate
	Construction	—			—			—		—
	Acquisition/development	—			—			—		—
	Multifamily	40			—			165		—
	Owner-occupied	986			7			879		3
	Non owner-occupied	1,045			13			625		7
	Total commercial real estate	2,071			20			1,669		10
	Residential real estate
	Senior lien	6,598			27			7,243		27
	Junior lien	1,539			14			1,566		15
	Total residential real estate	8,137			41			8,809		42
	Consumer	235			—			250		—
	Total impaired loans with a related allowance recorded	$	12,570		$	61		$	13,018	$	64
	Total impaired loans	$	31,076		$	262		$	33,821	$	320
Additional Information Related to Accruing TDR's	The table below provides additional information related to accruing TDRs at March 31, 2015 and December 31, 2014 (in thousands):
		Accruing TDRs
		31-Mar-15
		Recorded			Average			Unpaid		Unfunded
		investment			year-to-			principal		commitments
					date			balance		to fund
					recorded					TDRs
					investment
	Commercial	$	5,015		$	4,868		$	5,015	$	35
	Agriculture	99			99			103		—
	Commercial real estate	1,585			1,592			1,664		—
	Residential real estate	1,948			1,961			1,958		2
	Consumer	16			17			16		—
	Total	$	8,663		$	8,537		$	8,756	$	37
		Accruing TDRs
		December 31, 2014
		Recorded			Average			Unpaid		Unfunded
		investment			year-to-			principal		commitments
					date			balance		to fund
					recorded					TDRs
					investment
	Commercial	$	13,249		$	12,496		$	13,249	$	375
	Agriculture	2,711			3,110			2,715		—
	Commercial real estate	610			627			622		—
	Residential real estate	2,687			2,767			2,714		2
	Consumer	18			20			18		—
	Total	$	19,275		$	19,020		$	19,318	$	377
Summary of Company's Carrying Value of Non-Accrual TDR's	The following table summarizes the Company’s carrying value of non-accrual TDRs as of March 31, 2015 and December 31, 2014 (in thousands):
		Non - Accruing TDRs
		March 31, 2015						December 31, 2014
		Covered			Non-covered			Covered		Non-covered
	Commercial	$	1		$	3,693		$	1	$	3,993
	Agriculture	81			154			201		164
	Commercial real estate	83			327			94		364
	Residential real estate	898			1,029			910		1,056
	Consumer	—			185			—		190
	Total	$	1,063		$	5,388		$	1,206	$	5,767
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 three months ended March 31, 2015 and 2014 (in thousands):
		March 31,			March 31,
		2015			2014
	Accretable yield beginning balance	$	113,463		$	130,624
	Reclassification from non-accretable difference	11,186			6,164
	Reclassification to non-accretable difference	(1,137		)	(590		)
	Accretion	(12,694		)	(16,900		)
	Accretable yield ending balance	$	110,818		$	119,298
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 March 31, 2015 and December 31, 2014 (in thousands):
		March 31,			December 31,
		2015			2014
	Contractual cash flows	$	709,447		$	751,932
	Non-accretable difference	(348,775		)	(358,824		)
	Accretable yield	(110,818		)	(113,463		)
	Loans accounted for under ASC 310-30	$	249,854		$	279,645

Allowance_for_Loan_Losses_Tabl

Allowance for Loan Losses - (Tables)	3 Months Ended
	Mar. 31, 2015
Receivables [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 months ended March 31, 2015 and 2014 (in thousands):
		Three months ended March 31, 2015
		Commercial			Agriculture			Commercial			Residential			Consumer			Total
								real estate			real estate
	Beginning balance	$	8,598		$	1,009		$	3,819		$	3,771		$	416		$	17,613
	Non 310-30 beginning balance	8,598			541			3,597			3,743			413			16,892
	Charge-offs	(3		)	(47		)	(2		)	(82		)	(208		)	(342		)
	Recoveries	21			—			15			30			83			149
	Provision/recoupment	1,284			57			(82		)	96			48			1,403
	Non 310-30 ending balance	9,900			551			3,528			3,787			336			18,102
	ASC 310-30 beginning balance	—			468			222			28			3			721
	Charge-offs	—			—			—			—			—			—
	Recoveries	—			—			—			—			—			—
	Provision (recoupment)	20			132			(85		)	(28		)	11			50
	ASC 310-30 ending balance	20			600			137			—			14			771
	Ending balance	$	9,920		$	1,151		$	3,665		$	3,787		$	350		$	18,873
	Ending allowance balance attributable to:
	Non 310-30 loans individually evaluated for impairment	$	725		$	2		$	12		$	203		$	2		$	944
	Non 310-30 loans collectively evaluated for impairment	9,175			549			3,516			3,584			334			17,158
	ASC 310-30 loans	20			600			137			—			14			771
	Total ending allowance balance	$	9,920		$	1,151		$	3,665		$	3,787		$	350		$	18,873
	Loans:
	Non 310-30 individually evaluated for impairment	$	17,818		$	495		$	3,964		$	8,390		$	231		$	30,898
	Non 310-30 collectively evaluated for impairment	814,906			113,113			384,869			594,514			28,115			1,935,517
	ASC 310-30 loans	21,481			19,067			171,742			33,158			4,406			249,854
	Total loans	$	854,205		$	132,675		$	560,575		$	636,062		$	32,752		$	2,216,269
		Three months ended March 31, 2014
		Commercial			Agriculture			Commercial			Residential			Consumer			Total
								real estate			real estate
	Beginning balance	$	4,258		$	1,237		$	2,276		$	4,259		$	491		$	12,521
	Non 310-30 beginning balance	4,029			572			1,984			4,165			491			11,241
	Charge-offs	(386		)	—			—			(20		)	(171		)	(577		)
	Recoveries	58			—			37			90			76			261
	Provision (recoupment)	1,880			(24		)	(44		)	(66		)	77			1,823
	Non 310-30 ending balance	5,581			548			1,977			4,169			473			12,748
	ASC 310-30 beginning balance	229			665			292			94			—			1,280
	Charge-offs	(2		)	—			—			—			—			(2		)
	Recoveries	—			—			—			—			—			—
	Provision (recoupment)	(84		)	—			(56		)	(29		)	115			(54		)
	ASC 310-30 ending balance	143			665			236			65			115			1,224
	Ending balance	$	5,724		$	1,213		$	2,213		$	4,234		$	588		$	13,972
	Ending allowance balance attributable to:
	Non 310-30 loans individually evaluated for impairment	$	190		$	1		$	32		$	453		$	3		$	679
	Non 310-30 loans collectively evaluated for impairment	5,391			547			1,945			3,716			470			12,069
	ASC 310-30 loans	143			665			236			65			115			1,224
	Total ending allowance balance	$	5,724		$	1,213		$	2,213		$	4,234		$	588		$	13,972
	Loans:
	Non 310-30 individually evaluated for impairment	$	9,061		$	9,306		$	5,035		$	9,452		$	249		$	33,103
	Non 310-30 collectively evaluated for impairment	521,401			122,280			312,102			539,306			26,854			1,521,943
	ASC 310-30 loans	52,107			23,545			263,608			60,467			6,819			406,546
	Total loans	$	582,569		$	155,131		$	580,745		$	609,225		$	33,922		$	1,961,592

FDIC_Indemnification_Asset_Tab

FDIC Indemnification Asset - (Tables)	3 Months Ended
	Mar. 31, 2015
Banking and Thrift [Abstract]
Summary of Activity Related to FDIC Indemnification Asset	Below is a summary of the activity related to the FDIC indemnification asset during the three months ended March 31, 2015 and 2014 (in thousands):
		For the three months ended
		March 31,			March 31,
		2015			2014
	Balance at beginning of period	$	39,082		$	64,447
	Amortization	(7,670		)	(7,608		)
	FDIC portion of (recoveries) charge-offs exceeding fair value marks	(4,900		)	(133		)
	Changes for FDIC loss share submissions	1,342			(29		)
	Balance at end of period	$	27,854		$	56,677

Other_Real_Estate_Owned_Tables

Other Real Estate Owned - (Tables)	3 Months Ended
	Mar. 31, 2015
Banking and Thrift [Abstract]
Summary of Activity in OREO Balances	A summary of the activity in the OREO balances during the three months ended March 31, 2015 and 2014 is as follows (in thousands):
		For the three months ended March 31,
		2015			2014
	Beginning balance	$	29,120		$	70,125
	Transfers from loan portfolio, at fair value	498			236
	Impairments	(470		)	(822		)
	Sales	(7,202		)	(4,143		)
	Gain on sale of OREO, net	1,471			587
	Ending balance	$	23,417		$	65,983

Borrowings_Tables

Borrowings (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure of Repurchase Agreements [Abstract]
Federal Home Loan Bank, Advances	More information about FHLB advances at March 31, 2015 is detailed in the table below (dollars in thousands):
	Maturity Year	March 31, 2015		Rate
	2016	$	15,000	0.84	%
	2018	$	10,000	1.81	%
	2020	$	15,000	2.33	%

Regulatory_Capital_Tables

Regulatory Capital - (Tables)	3 Months Ended
	Mar. 31, 2015
Banking and Thrift [Abstract]
Capital Ratio Requirements under Prompt Corrective Action or Other Regulatory Requirements	At March 31, 2015 and December 31, 2014, the Bank 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):
		March 31, 2015
		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	14.1	%	$	684,742	N/A		N/A		4	%	$	193,916
	NBH Bank, N.A.	11.1	%	536,375		10	%	$	482,858	4	%	193,143
	Common equity tier 1 risk-based capital
	Consolidated	26.3	%	684,742		6.5	%	$	168,947	4.5	%	$	116,963
	NBH Bank, N.A.	20.8	%	536,375		6.5	%	167,683		4.5	%	116,088
	Tier 1 risk-based capital ratio (2)
	Consolidated	26.3	%	$	684,742	8	%	$	207,935	6	%	$	155,951
	NBH Bank, N.A.	20.8	%	536,375		11	%	283,771		6	%	154,784
	Total risk-based capital ratio (2)
	Consolidated	27.1	%	$	703,867	10	%	$	259,919	8	%	$	207,935
	NBH Bank, N.A.	21.5	%	555,499		12	%	309,568		8	%	206,379
		December 31, 2014
		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	15	%	$	712,222	N/A		N/A		4	%	$	190,148
	NBH Bank, N.A.	12.1	%	573,934		10	%	$	473,478	4	%	189,391
	Tier 1 risk-based capital ratio (2)
	Consolidated	28.9	%	$	712,222	6	%	$	147,796	4	%	$	98,530
	NBH Bank, N.A.	23.5	%	573,934		11	%	268,855		4	%	97,766
	Total risk-based capital ratio (2)
	Consolidated	29.6	%	$	730,086	10	%	$	246,326	8	%	$	197,061
	NBH Bank, N.A.	24.2	%	591,799		12	%	293,297		8	%	195,531
	-1	These ratio requirements for NBH Bank, N.A. are reflective of the agreements NBH Bank, N.A. has made with its various regulators in connection with the approval of its de novo charter.
	-2	Due to the conditional guarantee represented by the loss sharing agreements, the FDIC indemnification asset and the portion of assets covered by the FDIC loss sharing agreements are risk-weighted at 20% for purposes of risk-based capital computations.

FDIC_Loss_Sharing_Income_Table

FDIC Loss Sharing Income - (Tables)	3 Months Ended
	Mar. 31, 2015
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 (expense) income during the three months ended March 31, 2015 and 2014 (in thousands):
		For the three months ended
		March 31, 2015			March 31, 2014
	Clawback liability amortization	$	(368	)	$	(328	)
	Clawback liability remeasurement	(1,107		)	(516		)
	Reimbursement to FDIC for gain on sale of and income from covered OREO	(672		)	(918		)
	Reimbursement to FDIC for recoveries	(8		)	(85		)
	FDIC reimbursement of covered asset resolution costs	1,345			890
	Total	$	(810	)	$	(957	)

Stockbased_Compensation_and_Em1

Stock-based Compensation and Employee Benefits - (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Option Activity	The following table summarizes stock option activity for the three months ended March 31, 2015:
		Options		Weighted		Weighted	Aggregate
				Average		Average	Intrinsic
				Exercise		Remaining	Value
				Price		Contractual
						Term in
						Years
	Outstanding at December 31, 2014	3,597,111		$	19.9	4.46	$	223,211
	Granted	1,187		18.48
	Forfeited	(16,171	)	18.65
	Surrendered	—		—
	Exercised	—		—
	Expired	—		—
	Outstanding at March 31, 2015	3,582,127		$	19.9	4.22	$	83,653
	Options fully vested and exercisable at March 31, 2015	3,320,998		$	19.99	3.88	$	—
	Options expected to vest	254,057		$	18.89	8.21	$	68,271
Summary of Restricted Stock Activity	The following table summarizes restricted stock activity for the three months ended March 31, 2015:
		Total Restricted Shares		Weighted Average Grant-Date Fair Value
	Unvested at December 31, 2014	955,398		$	15.16
	Vested	—		—
	Granted	1,187		18.48
	Forfeited	(2,648	)	18.47
	Surrendered	—		—
	Unvested at March 31, 2015	953,937		$	15.15

Warrants_Tables

Warrants (Tables)	3 Months Ended
	Mar. 31, 2015
Warrants and Rights Note Disclosure [Abstract]
Schedule of Fair Value of Warrants Estimated Using Black-Scholes Option Pricing Model	The fair value of the warrants was estimated using a Black-Scholes option pricing model utilizing the following assumptions at the indicated dates:
		March 31, 2015		December 31, 2014
	Risk-free interest rate	1.35	%	1.67	%
	Expected volatility	24.76	%	24.18	%
	Expected term (years)	5-Apr		6-May
	Dividend yield	1.06	%	1.03	%

Income_Per_Share_Tables

Income Per Share - (Tables)	3 Months Ended
	Mar. 31, 2015
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 months ended March 31, 2015 and 2014 (in thousands, except share and earnings per share information):
		For the three months ended
		March 31,			March 31,
		2015			2014
	Distributed earnings	$	1,908		$	2,276
	Undistributed earnings (distributions in excess of earnings)	(662		)	(845		)
	Net income	$	1,246		$	1,431
	Less: earnings allocated to participating securities	(10		)	(5		)
	Earnings allocated to common shareholders	$	1,236		$	1,426
	Weighted average shares outstanding for basic earnings per common share	38,028,506			44,819,644
	Dilutive effect of equity awards	106			35,827
	Dilutive effect of warrants	—			7,667
	Weighted average shares outstanding for diluted earnings per common share	38,028,612			44,863,138
	Basic earnings per share	$	0.03		$	0.03
	Diluted earnings per share	$	0.03		$	0.03

Derivatives_Tables

Derivatives - (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Information about the valuation methods used to measure fair value is provided in note 17 of the unaudited consolidated financial statements.
				Asset Derivatives							Liability Derivatives
				Fair Value							Fair Value
		Balance Sheet Location		March 31, 2015			December 31, 2014			Balance Sheet Location	March 31, 2015		December 31, 2014
	Derivatives designated as hedging instruments
	Interest rate products	Other assets		$	38		$	10		Other liabilities	$	5,386	$	3,206
	Total derivatives designated as hedging instruments			$	38		$	10			$	5,386	$	3,206
	Derivatives not designated as hedging instruments
	Interest rate products	Other assets		$	2,018		$	1,418		Other liabilities	$	2,164	$	1,522
	Total derivatives not designated as hedging instruments			$	2,018		$	1,418			$	2,164	$	1,522
Derivative Instruments, Gain (Loss)	The tables below present the effect of the Company’s derivative financial instruments on the consolidated statement of operations for the three months ended March 31, 2015 and 2014 (in thousands).
	Derivatives in fair value hedging relationships		Location of loss recognized in income on derivatives	Amount of loss recognized in income on derivatives
				For the three months ended March 31,
				2015			2014
	Interest rate products		Interest income	$	(2,152	)	$	(614	)
	Total			$	(2,152	)	$	(614	)
	Derivatives in fair value hedging relationships		Location of gain recognized in income on derivatives	Amount of gain recognized in income on hedged items
				For the three months ended March 31,
				2015			2014
	Interest rate products		Interest income	$	2,013		$	541
	Total			$	2,013		$	541
				Amount of loss recognized in income on derivatives
				For the three months ended March 31,
	Derivatives not designated as hedging instruments		Location of loss recognized in income on derivatives	2015			2014
	Interest rate products		Other non-interest income	$	(39	)	(14	)
	Total			$	(39	)	(14	)

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Total Unfunded Commitments	Total unfunded commitments at March 31, 2015 and December 31, 2014 were as follows (in thousands):
		March 31, 2015						December 31, 2014
		Covered		Non-covered		Total		Covered		Non-covered		Total
	Commitments to fund loans
	Residential	$	—	$	2,669	$	2,669	$	—	$	1,683	$	1,683
	Commercial and commercial real estate	11		191,008		191,019		11		202,593		202,604
	Construction and land development	—		27,079		27,079		—		35,814		35,814
	Consumer	—		4,412		4,412		—		4,376		4,376
	Credit card lines of credit	—		17,717		17,717		—		18,065		18,065
	Unfunded commitments under lines of credit	5,581		220,107		225,688		7,645		215,305		222,950
	Commercial and standby letters of credit	234		10,140		10,374		234		9,731		9,965
	Total	$	5,826	$	473,132	$	478,958	$	7,890	$	487,567	$	495,457

Fair_Value_Measurements_Tables

Fair Value Measurements - (Tables)	3 Months Ended
	Mar. 31, 2015
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 March 31, 2015 and December 31, 2014 on the consolidated statements of financial condition utilizing the hierarchy structure described above (in thousands):
		March 31, 2015
		Level 1			Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	—		$	385,236		$	—	$	385,236
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—			1,027,759			—		1,027,759
	Other securities	—			—			419		419
	Derivatives	—			2,056			—		2,056
	Total assets at fair value	$	—		$	1,415,051		$	419	$	1,415,470
	Liabilities:
	Warrant liability	$	—		$	—		$	2,938	$	2,938
	Clawback liability	—			—			37,813		37,813
	Derivatives	—			7,550			—		7,550
	Total liabilities at fair value	$	—		$	7,550		$	40,751	$	48,301
		December 31, 2014
		Level 1			Level 2			Level 3		Total
	Assets:
	Investment securities available-for-sale:
	Mortgage-backed securities (“MBS”):
	Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	—		$	404,215		$	—	$	404,215
	Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	—			1,074,580			—		1,074,580
	Other securities	—			—			419		419
	Derivatives	—			1,428			—		1,428
	Total assets at fair value	$	—		$	1,480,223		$	419	$	1,480,642
	Liabilities:
	Warrant liability	$	—		$	—		$	3,328	$	3,328
	Clawback liability	—			—			36,338		36,338
	Derivatives	—			4,728			—		4,728
	Total liabilities at fair value	$	—		$	4,728		$	39,666	$	44,394
Table of Changes in Level 3 Financial Instruments	The table below details the changes in level 3 financial instruments during the three months ended March 31, 2015 and March 31, 2014 (in thousands):
		Warrant			Clawback
		liability			liability
	Balance at December 31, 2013	$	6,281		$	32,465
	Change in value	(898		)	516
	Amortization	—			328
	Net change in level 3	$	(898	)	$	844
	Balance at March 31, 2014	$	5,383		$	33,309
	Balance at December 31, 2014	$	3,328		$	36,338
	Change in value	(390		)	1,107
	Amortization	—			368
	Net change in Level 3	(390		)	1,475
	Balance at March 31, 2015	$	2,938		$	37,813
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 three months ended March 31, 2015 and 2014 (in thousands):
		March 31, 2015
		Total			Losses from fair value changes
	Other real estate owned	$	23,417		$	470
	Impaired loans	30,898			146
		31-Mar-14
		Total			Losses from fair value changes
	Other real estate owned	$	65,983		$	822
	Impaired loans	33,103			465
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 March 31, 2015. 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
		March 31,						Measures
		2015
	Other securities	$	419		Cash investment in private equity fund		Realizable value
	Impaired loans	30,898			Appraised value		Appraised values
							Discount rate	0-25%
	Clawback liability	37,813			Contractually defined discounted cash flows		Intrinsic loss estimates	$323.3 million -
								$405 million
							Expected credit losses	—
							Discount rate	4%
	Warrant liability	2,938			Black-Scholes		Volatility	18%-30%

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments - (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments
			31-Mar-15				31-Dec-14
		Level in fair	Carrying		Estimated		Carrying		Estimated
		value	amount		fair value		amount		fair value
		measurement
		hierarchy
	ASSETS:
	Cash and cash equivalents	Level 1	$	490,104	$	490,104	$	256,979	$	256,979
	Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	385,236		385,236		404,215		404,215
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises available-for-sale	Level 2	1,027,759		1,027,759		1,074,580		1,074,580
	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	400,408		408,251		422,622		428,323
	Mortgage-backed securities—other residential mortgage-backed securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	Level 2	103,202		102,552		107,968		106,314
	Capital stock of FHLB	Level 2	7,361		7,361		7,595		7,595
	Capital stock of FRB	Level 2	19,689		19,689		19,450		19,450
	Loans receivable, net	Level 3	2,197,396		2,255,644		2,144,796		2,193,222
	Loans held-for-sale	Level 2	4,935		4,935		5,146		5,146
	Accrued interest receivable	Level 2	12,070		12,070		11,465		11,465
	Derivatives	Level 2	2,056		2,056		1,428		1,428
	LIABILITIES:
	Deposit transaction accounts	Level 2	2,507,801		2,507,801		2,409,137		2,409,137
	Time deposits	Level 2	1,324,661		1,325,585		1,357,051		1,357,885
	Securities sold under agreements to repurchase	Level 2	284,161		284,161		133,552		133,552
	Federal Home Loan Bank advances	Level 2	40,000		40,790		40,000		40,465
	Due to FDIC	Level 3	37,813		37,813		42,011		42,011
	Warrant liability	Level 3	2,938		2,938		3,328		3,328
	Accrued interest payable	Level 2	3,804		3,804		3,608		3,608
	Derivatives	Level 2	7,550		7,550		4,728		4,728

Basis_of_Presentation_Details

Basis of Presentation - (Details)	3 Months Ended
	Mar. 31, 2015
	banking_center
Accounting Policies [Abstract]
Number Of Full Service Banking Offices	97

Investment_Securities_Narrativ

Investment Securities - (Narrative) (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Investments Schedule [Abstract]
Investment securities total	$1,900,000,000	$2,000,000,000
Available-for-sale securities	1,413,414,000	1,479,214,000
Held-to-maturity securities	503,610,000	530,590,000
Mortgage-backed securities as percentage of available-for-sale investment portfolio	100.00%	100.00%
Fair value of available-for-sale investment securities pledged as collateral	446,800,000	274,400,000
Estimated weighted average life of the available-for-sale mortgage-backed securities portfolio	3 years 4 months 3 days	3 years 5 months 15 days
Held-to-maturity investment securities pledged as collateral	$99,500,000	$88,300,000
Estimated weighted average expected life of the held-to-maturity mortgage-backed securities portfolio	3 years 2 months 29 days	3 years 4 months 10 days

Investment_Securities_Summary_

Investment Securities - (Summary of Available-for-Sale Investment Securities) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$1,407,411	$1,484,497
Gross unrealized gains	19,406	16,478
Gross unrealized losses	-13,403	-21,761
Investment securities available-for-sale (at fair value)	1,413,414	1,479,214
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	373,802	395,244
Gross unrealized gains	11,434	9,014
Gross unrealized losses	0	-43
Investment securities available-for-sale (at fair value)	385,236	404,215
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	1,033,190	1,088,834
Gross unrealized gains	7,972	7,464
Gross unrealized losses	-13,403	-21,718
Investment securities available-for-sale (at fair value)	1,027,759	1,074,580
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
Investment securities available-for-sale (at fair value)	$419	$419

Investment_Securities_Summary_1

Investment Securities - (Summary of Unrealized Losses) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Less than 12 months Fair Value	$75,887	$88,871
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	-1,305	-2,053
12 months or more, Fair Value	611,431	757,117
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	-12,098	-19,708
Total, Fair Value	687,318	845,988
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	-13,403	-21,761
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	0	17
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
12 months or more, Fair Value	0	89,749
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	-43
Total, Fair Value	0	89,766
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	-43
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	75,887	88,854
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	-1,305	-2,053
12 months or more, Fair Value	611,431	667,368
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	-12,098	-19,665
Total, Fair Value	687,318	756,222
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	($13,403)	($21,718)

Investment_Securities_Summary_2

Investment Securities - (Summary of Held-to-maturity Investment Securities) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	$503,610	$530,590
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	8,359	5,990
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	-1,166	-1,943
Fair value	510,803	534,637
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]
Held-to-maturity Securities	400,408	422,622
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	7,860	5,773
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	-17	-72
Fair value	408,251	428,323
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	103,202	107,968
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	499	217
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	-1,149	-1,871
Fair value	$102,552	$106,314

Investment_Securities_Summary_3

Investment Securities - (Summary of Held-to-Maturity Securities, Unrealized Losses) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]
Fair Value, Less than 12 months	$0	$0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Fair Value, 12 months or more	55,069	110,278
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	-1,166	-1,943
Total Fair Value	55,069	110,278
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	-1,166	-1,943
Residential Mortgage Backed Agency [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair Value, Less than 12 months	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Fair Value, 12 months or more	2,120	35,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	-17	-72
Total Fair Value	2,120	35,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	-17	-72
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Fair Value, Less than 12 months	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Fair Value, 12 months or more	52,949	75,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	-1,149	-1,871
Total Fair Value	52,949	75,139
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss	($1,149)	($1,871)

Loans_Narrative_Section_Detail

Loans - Narrative Section (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Debt Instrument [Line Items]
Covered Loans Percentage	7.80%	9.00%
Fees and cost related to loans	$9,500,000	$10,500,000
Carrying amount of loan investments	2,216,269,000	2,162,409,000	1,961,592,000
Energy Loans [Member]
Debt Instrument [Line Items]
Carrying amount of loan investments	149,600,000	161,800,000
Commercial Loan [Member]
Debt Instrument [Line Items]
Carrying amount of loan investments	854,205,000	795,396,000
Commercial Banking [Member]
Debt Instrument [Line Items]
Carrying amount of loan investments	194,600,000	130,600,000
Loans And Leases Receivable, Tax Exempt	176,600,000	112,600,000
Non Accrual [Member]
Debt Instrument [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	11,358,000	10,813,000
ASC 310-30 [Member]
Debt Instrument [Line Items]
Carrying amount of loan investments	249,854,000	279,645,000
ASC 310-30 [Member] | Commercial Loan [Member]
Debt Instrument [Line Items]
Carrying amount of loan investments	$21,481,000	$22,956,000

Loans_Impaired_Loans_Narrative

Loans - Impaired Loans Narrative (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Impaired loans	$9,700
Recorded investment of impaired loans	30,898	32,091
Impaired loans which were covered by FDIC loss sharing agreement		193,697
Collective related allowance for loan losses for impaired loans	942	279
Discounted Cash Flows [Member]
Debt Instrument [Line Items]
Impaired loans	3,900
Fair Value Of Collateral Pledged [Member]
Debt Instrument [Line Items]
Impaired loans	17,300
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	$11,000	$11,100

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 $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Loans [Line Items]
Total Loans	$2,216,269	$2,162,409	$1,961,592
Covered Loans Percentage	7.80%	9.00%
% of Total	100.00%	100.00%
Covered [Member]
Loans [Line Items]
Total Loans	171,887	193,697
Non-Covered [Member]
Loans [Line Items]
Total Loans	2,044,382	1,968,712
% of Total	92.20%	91.00%
Commercial Loan [Member]
Loans [Line Items]
Total Loans	854,205	795,396
% of Total	38.50%	36.80%
Agriculture [Member]
Loans [Line Items]
Total Loans	132,675	137,531
% of Total	6.00%	6.40%
Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	560,575	561,594
% of Total	25.30%	26.00%
Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	636,062	632,700
% of Total	28.70%	29.20%
Consumer [Member]
Loans [Line Items]
Total Loans	32,752	35,188
% of Total	1.50%	1.60%
Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	1,966,415	1,882,764
Non ASC 310-30 [Member] | Covered [Member]
Loans [Line Items]
Total Loans	29,542	32,821
Non ASC 310-30 [Member] | Non-Covered [Member]
Loans [Line Items]
Total Loans	1,936,873	1,849,943
Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	832,724	772,440
Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	113,608	118,468
Non ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	388,833	369,264
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	602,904	591,939
Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	28,346	30,653
ASC 310-30 [Member]
Loans [Line Items]
Total Loans	249,854	279,645
ASC 310-30 [Member] | Covered [Member]
Loans [Line Items]
Total Loans	142,345	160,876
ASC 310-30 [Member] | Non-Covered [Member]
Loans [Line Items]
Total Loans	107,509	118,769
ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	21,481	22,956
ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	19,067	19,063
ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	171,742	192,330
ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	33,158	40,761
ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	$4,406	$4,535

Loans_Loan_Delinquency_Detail

Loans - (Loan Delinquency) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Loans [Line Items]
Total loans	$2,216,269	$2,162,409	$1,961,592
Commercial Loan [Member]
Loans [Line Items]
Total loans	854,205	795,396
Agriculture [Member]
Loans [Line Items]
Total loans	132,675	137,531
Commercial Real Estate [Member]
Loans [Line Items]
Total loans	560,575	561,594
Residential Real Estate Segment [Member]
Loans [Line Items]
Total loans	636,062	632,700
Consumer [Member]
Loans [Line Items]
Total loans	32,752	35,188
Non ASC 310-30 [Member]
Loans [Line Items]
Total loans	1,966,415	1,882,764
Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total loans	832,724	772,440
Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total loans	113,608	118,468
Non ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total loans	388,833	369,264
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total loans	602,904	591,939
Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total loans	28,346	30,653
ASC 310-30 [Member]
Loans [Line Items]
Total loans	249,854	279,645
ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total loans	21,481	22,956
ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total loans	19,067	19,063
ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total loans	171,742	192,330
ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total loans	33,158	40,761
ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total loans	4,406	4,535
Covered Loan [Member]
Loans [Line Items]
Total loans	171,887	193,697
Covered Loan [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total loans	29,542	32,821
Covered Loan [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total loans	142,345	160,876
Non-Covered [Member]
Loans [Line Items]
Total loans	2,044,382	1,968,712
Non-Covered [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total loans	1,936,873	1,849,943
Non-Covered [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total loans	107,509	118,769
Total Loans [Member]
Loans [Line Items]
30-59 days past due	2,361	4,541
60-89 days past due	836	5,518
Greater than 90 days past due	27,331	35,358
Total past due	30,528	45,417
Current	2,185,741	2,116,992
Total loans	2,216,269	2,162,409
Loans 90 days past due and still accruing	24,971	34,097
Non- accrual	11,358	10,813
Total Loans [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
30-59 days past due	1,051	1,442
60-89 days past due	408	1,600
Greater than 90 days past due	2,533	1,523
Total past due	3,992	4,565
Current	1,962,423	1,878,199
Total loans	1,966,415	1,882,764
Loans 90 days past due and still accruing	174	263
Non- accrual	11,358	10,813
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	6,718	11,748
Total loans	6,718	11,748
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	0	41
60-89 days past due	0	0
Greater than 90 days past due	0	0
Total past due	0	41
Current	4,098	4,532
Total loans	4,098	4,573
Loans 90 days past due and still accruing	0	0
Non- accrual	0	0
Total Loans [Member] | Non ASC 310-30 [Member] | Multifamily [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	17,324	10,856
Total loans	17,324	10,856
Loans 90 days past due and still accruing	-1	-1
Non- accrual	0	0
Total Loans [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
30-59 days past due	57	336
60-89 days past due	146	78
Greater than 90 days past due	116	101
Total past due	319	515
Current	132,873	119,710
Total loans	133,192	120,225
Loans 90 days past due and still accruing	0	0
Non- accrual	778	843
Total Loans [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
30-59 days past due	105	158
60-89 days past due	51	0
Greater than 90 days past due	220	222
Total past due	376	380
Current	227,125	221,482
Total loans	227,501	221,862
Loans 90 days past due and still accruing	0	0
Non- accrual	220	222
Total Loans [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
30-59 days past due	162	535
60-89 days past due	197	78
Greater than 90 days past due	336	323
Total past due	695	936
Current	388,138	368,328
Total loans	388,833	369,264
Loans 90 days past due and still accruing	-1	-1
Non- accrual	998	1,065
Total Loans [Member] | Non ASC 310-30 [Member] | Sr lien [Member]
Loans [Line Items]
30-59 days past due	363	378
60-89 days past due	85	1,403
Greater than 90 days past due	653	732
Total past due	1,101	2,513
Current	550,056	537,022
Total loans	551,157	539,535
Loans 90 days past due and still accruing	0	0
Non- accrual	4,438	4,335
Total Loans [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]
Loans [Line Items]
30-59 days past due	24	133
60-89 days past due	18	1
Greater than 90 days past due	180	101
Total past due	222	235
Current	51,525	52,169
Total loans	51,747	52,404
Loans 90 days past due and still accruing	88	0
Non- accrual	509	476
Total Loans [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
30-59 days past due	0	17
60-89 days past due	48	1,016
Greater than 90 days past due	227	152
Total past due	275	1,185
Current	29,267	31,636
Total loans	29,542	32,821
Loans 90 days past due and still accruing	75	75
Non- accrual	1,154	1,317
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	1,051	1,425
60-89 days past due	360	584
Greater than 90 days past due	2,306	1,371
Total past due	3,717	3,380
Current	1,933,156	1,846,563
Total loans	1,936,873	1,849,943
Loans 90 days past due and still accruing	99	188
Non- accrual	10,204	9,496
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
30-59 days past due	306	83
60-89 days past due	71	97
Greater than 90 days past due	1,142	318
Total past due	1,519	498
Current	831,205	771,942
Total loans	832,724	772,440
Loans 90 days past due and still accruing	81	215
Non- accrual	4,803	4,215
Total Loans [Member] | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
30-59 days past due	0	47
60-89 days past due	36	0
Greater than 90 days past due	33	10
Total past due	69	57
Current	113,539	118,411
Total loans	113,608	118,468
Loans 90 days past due and still accruing	0	10
Non- accrual	396	495
Total Loans [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
30-59 days past due	387	511
60-89 days past due	103	1,404
Greater than 90 days past due	833	833
Total past due	1,323	2,748
Current	601,581	589,191
Total loans	602,904	591,939
Loans 90 days past due and still accruing	88	0
Non- accrual	4,947	4,811
Total Loans [Member] | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
30-59 days past due	196	266
60-89 days past due	1	21
Greater than 90 days past due	189	39
Total past due	386	326
Current	27,960	30,327
Total loans	28,346	30,653
Loans 90 days past due and still accruing	6	39
Non- accrual	214	227
Total Loans [Member] | ASC 310-30 [Member]
Loans [Line Items]
30-59 days past due	1,310	3,099
60-89 days past due	428	3,918
Greater than 90 days past due	24,798	33,835
Total past due	26,536	40,852
Current	223,318	238,793
Total loans	249,854	279,645
Loans 90 days past due and still accruing	24,797	33,834
Non- accrual	0	0
Total Loans [Member] | ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
30-59 days past due	275	152
60-89 days past due	0	0
Greater than 90 days past due	1,771	1,755
Total past due	2,046	1,907
Current	19,435	21,049
Total loans	21,481	22,956
Loans 90 days past due and still accruing	1,771	1,754
Non- accrual	0	0
Total Loans [Member] | ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
30-59 days past due	21	0
60-89 days past due	0	0
Greater than 90 days past due	380	367
Total past due	401	367
Current	18,666	18,696
Total loans	19,067	19,063
Loans 90 days past due and still accruing	379	367
Non- accrual	0	0
Total Loans [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
30-59 days past due	157	564
60-89 days past due	170	92
Greater than 90 days past due	22,263	31,013
Total past due	22,590	31,669
Current	149,152	160,661
Total loans	171,742	192,330
Loans 90 days past due and still accruing	22,263	31,013
Non- accrual	0	0
Total Loans [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
30-59 days past due	684	2,014
60-89 days past due	254	3,826
Greater than 90 days past due	335	646
Total past due	1,273	6,486
Current	31,885	34,275
Total loans	33,158	40,761
Loans 90 days past due and still accruing	335	646
Non- accrual	0	0
Total Loans [Member] | ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
30-59 days past due	173	369
60-89 days past due	4	0
Greater than 90 days past due	49	54
Total past due	226	423
Current	4,180	4,112
Total loans	4,406	4,535
Loans 90 days past due and still accruing	49	54
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	391	576
60-89 days past due	44	3,892
Greater than 90 days past due	22,276	31,239
Total past due	22,711	35,707
Current	119,634	125,169
Total loans	142,345	160,876
Loans 90 days past due and still accruing	22,276	31,238
Non- accrual	0	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	919	2,523
60-89 days past due	384	26
Greater than 90 days past due	2,522	2,596
Total past due	3,825	5,145
Current	103,684	113,624
Total loans	107,509	118,769
Loans 90 days past due and still accruing	2,521	2,596
Non- accrual	0	0
Total Loans [Member] | Covered Loan [Member]
Loans [Line Items]
30-59 days past due	391	593
60-89 days past due	92	4,908
Greater than 90 days past due	22,503	31,391
Total past due	22,986	36,892
Current	148,901	156,805
Total loans	171,887	193,697
Loans 90 days past due and still accruing	22,351	31,313
Non- accrual	1,154	1,317
Total Loans [Member] | Non-Covered [Member]
Loans [Line Items]
30-59 days past due	1,970	3,948
60-89 days past due	744	610
Greater than 90 days past due	4,828	3,967
Total past due	7,542	8,525
Current	2,036,840	1,960,187
Total loans	2,044,382	1,968,712
Loans 90 days past due and still accruing	2,620	2,784
Non- accrual	10,204	9,496
Total Loans [Member] | Covered And Non-covered [Member]
Loans [Line Items]
30-59 days past due	2,361	4,541
60-89 days past due	836	5,518
Greater than 90 days past due	27,331	35,358
Total past due	30,528	45,417
Current	2,185,741	2,116,992
Total loans	2,216,269	2,162,409
Loans 90 days past due and still accruing	24,971	34,097
Non- accrual	11,358	10,813
Non Accrual [Member]
Loans [Line Items]
Non- accrual	11,358	10,813
Non Accrual [Member] | Covered Loan [Member] | ASC 310-30 [Member] | Total Loans [Member]
Loans [Line Items]
Non- accrual	$0	$0

Loans_Credit_Exposure_for_Loan

Loans - (Credit Exposure for Loans as Determined by Company's Internal Risk Rating System) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Loans [Line Items]
Total Loans	$2,216,269	$2,162,409	$1,961,592
Agriculture [Member]
Loans [Line Items]
Total Loans	132,675	137,531
Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	636,062	632,700
Consumer [Member]
Loans [Line Items]
Total Loans	32,752	35,188
Commercial Loan [Member]
Loans [Line Items]
Total Loans	854,205	795,396
Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	560,575	561,594
Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	1,966,415	1,882,764
Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	113,608	118,468
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	602,904	591,939
Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	28,346	30,653
Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	832,724	772,440
Non ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	388,833	369,264
ASC 310-30 [Member]
Loans [Line Items]
Total Loans	249,854	279,645
ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	19,067	19,063
ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	33,158	40,761
ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	4,406	4,535
ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	21,481	22,956
ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	171,742	192,330
Covered [Member]
Loans [Line Items]
Total Loans	171,887	193,697
Covered [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	29,542	32,821
Covered [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total Loans	142,345	160,876
Non-Covered [Member]
Loans [Line Items]
Total Loans	2,044,382	1,968,712
Non-Covered [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	1,936,873	1,849,943
Non-Covered [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total Loans	107,509	118,769
Total Loans [Member]
Loans [Line Items]
Total Loans	2,216,269	2,162,409
Total Loans [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	1,966,415	1,882,764
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]
Loans [Line Items]
Total Loans	6,718	11,748
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]
Loans [Line Items]
Total Loans	4,098	4,573
Total Loans [Member] | Non ASC 310-30 [Member] | Multifamily [Member]
Loans [Line Items]
Total Loans	17,324	10,856
Total Loans [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total Loans	133,192	120,225
Total Loans [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total Loans	227,501	221,862
Total Loans [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	388,833	369,264
Total Loans [Member] | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	113,608	118,468
Total Loans [Member] | Non ASC 310-30 [Member] | Sr lien [Member]
Loans [Line Items]
Total Loans	551,157	539,535
Total Loans [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]
Loans [Line Items]
Total Loans	51,747	52,404
Total Loans [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	602,904	591,939
Total Loans [Member] | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	28,346	30,653
Total Loans [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	29,542	32,821
Total Loans [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	1,936,873	1,849,943
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	832,724	772,440
Total Loans [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total Loans	249,854	279,645
Total Loans [Member] | ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	19,067	19,063
Total Loans [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	33,158	40,761
Total Loans [Member] | ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	4,406	4,535
Total Loans [Member] | ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	21,481	22,956
Total Loans [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	171,742	192,330
Total Loans [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]
Loans [Line Items]
Total Loans	142,345	160,876
Total Loans [Member] | ASC 310-30 [Member] | Non-covered loans accounted for under ASC Topic 310-30 [Member]
Loans [Line Items]
Total Loans	107,509	118,769
Total Loans [Member] | Pass [Member]
Loans [Line Items]
Total Loans	2,021,329	1,958,078
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	1,889,224	1,814,873
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]
Loans [Line Items]
Total Loans	6,718	11,748
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]
Loans [Line Items]
Total Loans	4,098	4,573
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Multifamily [Member]
Loans [Line Items]
Total Loans	17,324	10,856
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total Loans	128,289	115,178
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total Loans	206,603	199,817
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	363,032	342,172
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	111,118	114,642
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Sr lien [Member]
Loans [Line Items]
Total Loans	545,049	533,630
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]
Loans [Line Items]
Total Loans	50,435	51,059
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	595,484	584,689
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	28,131	30,426
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	18,097	21,240
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	1,871,127	1,793,633
Total Loans [Member] | Pass [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	791,459	742,944
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total Loans	132,105	143,205
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	16,827	16,854
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	24,415	29,069
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	3,599	3,641
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	10,148	11,038
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	77,116	82,603
Total Loans [Member] | Pass [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]
Loans [Line Items]
Total Loans	47,426	49,856
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	84,679	93,349
Total Loans [Member] | Special Mention [Member]
Loans [Line Items]
Total Loans	46,945	33,629
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	41,710	28,039
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	0	0
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Multifamily [Member]
Loans [Line Items]
Total Loans	0	0
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total Loans	154	158
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total Loans	17,408	17,607
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	17,562	17,765
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	1,599	85
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Sr lien [Member]
Loans [Line Items]
Total Loans	0	23
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]
Loans [Line Items]
Total Loans	0	0
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	0	23
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	167	171
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	41,543	27,868
Total Loans [Member] | Special Mention [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	22,549	10,166
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total Loans	5,235	5,590
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	31	30
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	1,258	1,403
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	100	105
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	217	282
Total Loans [Member] | Special Mention [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	3,629	3,770
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	2,912	3,036
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	2,323	2,554
Total Loans [Member] | Substandard [Member]
Loans [Line Items]
Total Loans	142,763	165,941
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	34,579	39,626
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	0	0
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Multifamily [Member]
Loans [Line Items]
Total Loans	0	0
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total Loans	4,749	4,889
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total Loans	3,483	4,430
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	8,232	9,319
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	891	3,741
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Sr lien [Member]
Loans [Line Items]
Total Loans	5,951	5,744
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]
Loans [Line Items]
Total Loans	1,298	1,345
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	7,249	7,089
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	215	227
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	11,180	11,301
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	23,399	28,325
Total Loans [Member] | Substandard [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	17,992	19,250
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total Loans	108,184	126,315
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total Loans	2,209	2,179
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	7,485	10,289
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	707	789
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	10,555	11,092
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	87,228	101,966
Total Loans [Member] | Substandard [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]
Loans [Line Items]
Total Loans	87,677	103,451
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	20,507	22,864
Total Loans [Member] | Doubtful [Member]
Loans [Line Items]
Total Loans	5,232	4,761
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total Loans	902	226
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	0	0
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	7	8
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	7	8
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	157	138
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Jr Liens [Member]
Loans [Line Items]
Total Loans	14	0
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total Loans	171	138
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total Loans	0	0
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	98	109
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Non-covered loans excluded from ASC 310-30 [Member]
Loans [Line Items]
Total Loans	804	117
Total Loans [Member] | Doubtful [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total Loans	724	80
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total Loans	4,330	4,535
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	561	544
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total Loans	3,769	3,991
Total Loans [Member] | Doubtful [Member] | ASC 310-30 [Member] | Covered loans accounted for under ASC Topic 310-30 [Member]
Loans [Line Items]
Total Loans	4,330	4,533
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	0	2
Total Loans [Member] | Covered [Member]
Loans [Line Items]
Total Loans	171,887	193,697
Total Loans [Member] | Covered [Member] | Pass [Member]
Loans [Line Items]
Total Loans	65,523	71,096
Total Loans [Member] | Covered [Member] | Special Mention [Member]
Loans [Line Items]
Total Loans	3,079	3,207
Total Loans [Member] | Covered [Member] | Substandard [Member]
Loans [Line Items]
Total Loans	98,857	114,752
Total Loans [Member] | Covered [Member] | Doubtful [Member]
Loans [Line Items]
Total Loans	4,428	4,642
Total Loans [Member] | Non-Covered [Member]
Loans [Line Items]
Total Loans	2,044,382	1,968,712
Total Loans [Member] | Non-Covered [Member] | Pass [Member]
Loans [Line Items]
Total Loans	1,955,806	1,886,982
Total Loans [Member] | Non-Covered [Member] | Special Mention [Member]
Loans [Line Items]
Total Loans	43,866	30,422
Total Loans [Member] | Non-Covered [Member] | Substandard [Member]
Loans [Line Items]
Total Loans	43,906	51,189
Total Loans [Member] | Non-Covered [Member] | Doubtful [Member]
Loans [Line Items]
Total Loans	804	119
Total Loans [Member] | Covered And Non-covered [Member]
Loans [Line Items]
Total Loans	2,216,269	2,162,409
Total Loans [Member] | Covered And Non-covered [Member] | Pass [Member]
Loans [Line Items]
Total Loans	2,021,329	1,958,078
Total Loans [Member] | Covered And Non-covered [Member] | Special Mention [Member]
Loans [Line Items]
Total Loans	46,945	33,629
Total Loans [Member] | Covered And Non-covered [Member] | Substandard [Member]
Loans [Line Items]
Total Loans	142,763	165,941
Total Loans [Member] | Covered And Non-covered [Member] | Doubtful [Member]
Loans [Line Items]
Total Loans	$5,232	$4,761

Loans_Additional_Information_R

Loans - (Additional Information Regarding Impaired Loans) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Loans [Line Items]
Unpaid principal balance, Total	$33,298	$34,813
Recorded Investment In Acquired Impaired Loans	30,898	32,091
Loans and Leases Receivable, Allowance	942	279
Commercial Loan [Member]
Loans [Line Items]
Unpaid principal balance with no related allowance recorded	16,485	16,953
Recorded investment with no related allowance recorded	16,290	16,771
Allowance for loan losses allocated with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	1,720	894
Recorded investment of impaired loans with an allowance recorded	1,528	693
Allowance for loan losses allocated with an allowance recorded	725	82
Agriculture [Member]
Loans [Line Items]
Unpaid principal balance with no related allowance recorded	0	3,065
Recorded investment with no related allowance recorded	0	3,061
Allowance for loan losses allocated with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	555	177
Recorded investment of impaired loans with an allowance recorded	495	145
Allowance for loan losses allocated with an allowance recorded	2	0
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
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
Commercial Acquisition/Development [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
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
Multifamily [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
Unpaid principal balance of impaired loans with an allowance recorded	40	0
Recorded investment of impaired loans with an allowance recorded	39	0
Allowance for loan losses allocated with an allowance recorded	0	0
Owner-Occupied [Member]
Loans [Line Items]
Unpaid principal balance with no related allowance recorded	2,188	1,164
Recorded investment with no related allowance recorded	1,923	970
Allowance for loan losses allocated with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	1,275	1,321
Recorded investment of impaired loans with an allowance recorded	965	1,024
Allowance for loan losses allocated with an allowance recorded	3	5
Non Owner-Occupied [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
Unpaid principal balance of impaired loans with an allowance recorded	1,120	1,140
Recorded investment of impaired loans with an allowance recorded	1,037	1,060
Allowance for loan losses allocated with an allowance recorded	8	9
Total Commercial Real Estate [Member]
Loans [Line Items]
Unpaid principal balance with no related allowance recorded	2,188	1,164
Recorded investment with no related allowance recorded	1,923	970
Allowance for loan losses allocated with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	2,435	2,461
Recorded investment of impaired loans with an allowance recorded	2,041	2,084
Allowance for loan losses allocated with an allowance recorded	11	14
Sr Lien 1-4 Family Closed End [Member]
Loans [Line Items]
Unpaid principal balance with no related allowance recorded	354	694
Recorded investment with no related allowance recorded	316	248
Allowance for loan losses allocated with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	7,508	7,360
Recorded investment of impaired loans with an allowance recorded	6,547	6,359
Allowance for loan losses allocated with an allowance recorded	180	172
Jr Lien 1-4 Family Closed End [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
Unpaid principal balance of impaired loans with an allowance recorded	1,785	1,768
Recorded investment of impaired loans with an allowance recorded	1,527	1,515
Allowance for loan losses allocated with an allowance recorded	22	9
Residential Real Estate Segment [Member]
Loans [Line Items]
Unpaid principal balance with no related allowance recorded	354	694
Recorded investment with no related allowance recorded	316	248
Allowance for loan losses allocated with no related allowance recorded	0	0
Unpaid principal balance of impaired loans with an allowance recorded	9,293	9,128
Recorded investment of impaired loans with an allowance recorded	8,074	7,874
Allowance for loan losses allocated with an allowance recorded	202	181
Consumer [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
Unpaid principal balance of impaired loans with an allowance recorded	268	277
Recorded investment of impaired loans with an allowance recorded	231	245
Allowance for loan losses allocated with an allowance recorded	2	2
Impaired Loans With No Related Allowance Recorded [Member] [Member]
Loans [Line Items]
Unpaid principal balance with no related allowance recorded	19,027	21,876
Recorded investment with no related allowance recorded	18,529	21,050
Allowance for loan losses allocated with no related allowance recorded	0	0
Impaired Loans with Related Allowance Recorded [Member]
Loans [Line Items]
Unpaid principal balance of impaired loans with an allowance recorded	14,271	12,937
Recorded investment of impaired loans with an allowance recorded	12,369	11,041
Allowance for loan losses allocated with an allowance recorded	$942	$279

Loans_Impaired_Loans_Average_R

Loans (Impaired Loans - Average Recorded Investment and Interest Income Recognized) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Loans [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$31,076	$33,821
Impaired Financing Receivable, Interest Income, Cash Basis Method	262	320
Commercial Loan [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	16,252	7,562
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	176	94
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,544	2,113
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	12
Agriculture [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	9,132
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	119
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	583	177
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Commercial Construction [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Commercial Acquisition/Development [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	398
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	5
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Multifamily [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	908
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	40	165
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Owner-Occupied [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,935	1,622
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	25	26
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	986	879
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	7	3
Non Owner-Occupied [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	480
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	8
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,045	625
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	13	7
Total Commercial Real Estate [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,935	3,408
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	25	39
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	2,071	1,669
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	20	10
Sr Lien 1-4 Family Closed End [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	319	701
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	4
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	6,598	7,243
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	27	27
Jr Lien 1-4 Family Closed End [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,539	1,566
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	14	15
Residential Real Estate Segment [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	319	701
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	4
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	8,137	8,809
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	41	42
Consumer [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	0
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	235	250
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	0	0
Impaired Loans With No Related Allowance Recorded [Member] [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	18,506	20,803
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	201	256
Impaired Loans with Related Allowance Recorded [Member]
Loans [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	12,570	13,018
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	$61	$64

Loans_Troubled_Debt_Restructur

Loans - Troubled Debt Restructuring and Loans Accounted for Under ASC Topic 310-30 Narratives (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
	SecurityLoan	SecurityLoan
Debt Instrument [Line Items]
Accretable yield related for loan pool	$110,818,000	$119,298,000	$113,463,000	$130,624,000
TDR’s modified within the past year that defaulted on their restructured terms	0	2
Carrying amount of loan investments	2,216,269,000	1,961,592,000	2,162,409,000
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0
Troubled Debt Restructurings [Member]
Debt Instrument [Line Items]
Number of restructured loans	9
Recorded investment	1,200,000
Troubled Debt Restructurings [Member] | Non Accrual [Member]
Debt Instrument [Line Items]
Carrying amount of loan investments	6,500,000		7,000,000
FDIC Covered [Member]
Debt Instrument [Line Items]
Accruing troubled debt restructurings	1,800,000		9,800,000
Agriculture and Consumer loans [Member]
Debt Instrument [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		26,000
Accrual Status [Member]
Debt Instrument [Line Items]
Financing Receivable, Modifications, Subsequent Compliance Recorded Investment	8,800,000
Recorded investment	8,663,000		19,275,000
Covered [Member]
Debt Instrument [Line Items]
Carrying amount of loan investments	171,887,000		193,697,000
Covered [Member] | Non Accrual Status [Member]
Debt Instrument [Line Items]
Troubled Debt Restructuring Nonaccrual Loans	$1,063,000		$1,206,000

Loans_Additional_Information_R1

Loans - (Additional Information Related to Accruing TDR's) (Detail) (Accruing TDR [Member], USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Loans [Line Items]
Recorded investment	$8,663	$19,275
Average year-to- date recorded investment	8,537	19,020
Unpaid principal balance	8,756	19,318
Unfunded commitments to fund TDRs	37	377
Commercial [Member]
Loans [Line Items]
Recorded investment	5,015	13,249
Average year-to- date recorded investment	4,868	12,496
Unpaid principal balance	5,015	13,249
Unfunded commitments to fund TDRs	35	375
Agriculture [Member]
Loans [Line Items]
Recorded investment	99	2,711
Average year-to- date recorded investment	99	3,110
Unpaid principal balance	103	2,715
Unfunded commitments to fund TDRs	0	0
Commercial Real Estate [Member]
Loans [Line Items]
Recorded investment	1,585	610
Average year-to- date recorded investment	1,592	627
Unpaid principal balance	1,664	622
Unfunded commitments to fund TDRs	0	0
Residential Real Estate Segment [Member]
Loans [Line Items]
Recorded investment	1,948	2,687
Average year-to- date recorded investment	1,961	2,767
Unpaid principal balance	1,958	2,714
Unfunded commitments to fund TDRs	2	2
Consumer [Member]
Loans [Line Items]
Recorded investment	16	18
Average year-to- date recorded investment	17	20
Unpaid principal balance	16	18
Unfunded commitments to fund TDRs	$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 $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Covered [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	$1,063	$1,206
Covered [Member] | Commercial [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	1	1
Covered [Member] | Agriculture [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	81	201
Covered [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	83	94
Covered [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	898	910
Covered [Member] | Consumer [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	0	0
Non-Covered [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	5,388	5,767
Non-Covered [Member] | Commercial [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	3,693	3,993
Non-Covered [Member] | Agriculture [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	154	164
Non-Covered [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	327	364
Non-Covered [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	1,029	1,056
Non-Covered [Member] | Consumer [Member]
Loans [Line Items]
Carrying Value of Non - Accruing TDR’s	$185	$190

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 $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Accretable yield beginning balance	$113,463	$130,624
Reclassification from non-accretable difference	11,186	6,164
Reclassification to non-accretable difference	-1,137	-590
Accretion	-12,694	-16,900
Accretable yield ending balance	$110,818	$119,298

Loans_Composition_of_Net_Book_

Loans - (Composition of Net Book Value for Loans Accounted for under ASC Topic 310-30) (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Contractual cash flows	$709,447	$751,932
Non-accretable difference	-348,775	-358,824
Accretable yield	-110,818	-113,463
Loans accounted for under ASC 310-30	$249,854	$279,645

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
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$17,613	$12,521
Provision for loan losses	1,453	1,769
Ending balance	18,873	13,972
Total ending allowance balance	18,873	13,972
Total Loans	2,216,269	1,961,592	2,162,409
Non ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	16,892	11,241
Charge-offs	-342	-577
Recoveries	149	261
Provision for loan losses	1,403	1,823
Ending balance	18,102	12,748
Ending allowance balance individually evaluated for impairment	944	679
Ending allowance balance collectively evaluated for impairment	17,158	12,069
Total ending allowance balance	18,102	12,748
Loans individually evaluated for impairment	30,898	33,103
Loans collectively evaluated for impairment	1,935,517	1,521,943
Total Loans	1,966,415		1,882,764
ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	721	1,280
Charge-offs	0	-2
Recoveries	0	0
Provision for loan losses	50	-54
Ending balance	771	1,224
Ending allowance balance	771	1,224
Total ending allowance balance	771	1,224
Loans	249,854	406,546
Total Loans	249,854		279,645
Commercial Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance			8,598	4,258
Ending balance	9,920	5,724	8,598	4,258
Total ending allowance balance	9,920	5,724	8,598	4,258
Total Loans	854,205	582,569
Commercial Portfolio Segment [Member] | Non ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	8,598	4,029
Charge-offs	-3	-386
Recoveries	21	58
Provision for loan losses	1,284	1,880
Ending balance	9,900	5,581
Ending allowance balance individually evaluated for impairment	725	190
Ending allowance balance collectively evaluated for impairment	9,175	5,391
Total ending allowance balance	9,900	5,581
Loans individually evaluated for impairment	17,818	9,061
Loans collectively evaluated for impairment	814,906	521,401
Commercial Portfolio Segment [Member] | ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	0	229
Charge-offs	0	-2
Recoveries	0	0
Provision for loan losses	20	-84
Ending balance	20	143
Ending allowance balance	20	143
Total ending allowance balance	20	143
Loans	21,481	52,107
Agriculture [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance			1,009	1,237
Ending balance	1,151	1,213	1,009	1,237
Total ending allowance balance	1,151	1,213	1,009	1,237
Total Loans	132,675	155,131
Agriculture [Member] | Non ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	541	572
Charge-offs	-47	0
Recoveries	0	0
Provision for loan losses	57	-24
Ending balance	551	548
Ending allowance balance individually evaluated for impairment	2	1
Ending allowance balance collectively evaluated for impairment	549	547
Total ending allowance balance	551	548
Loans individually evaluated for impairment	495	9,306
Loans collectively evaluated for impairment	113,113	122,280
Agriculture [Member] | ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	468	665
Charge-offs	0	0
Recoveries	0	0
Provision for loan losses	132	0
Ending balance	600	665
Ending allowance balance	600	665
Total ending allowance balance	600	665
Loans	19,067	23,545
Commercial Real Estate Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance			3,819	2,276
Ending balance	3,665	2,213	3,819	2,276
Total ending allowance balance	3,665	2,213	3,819	2,276
Total Loans	560,575	580,745
Commercial Real Estate Portfolio Segment [Member] | Non ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,597	1,984
Charge-offs	-2	0
Recoveries	15	37
Provision for loan losses	-82	-44
Ending balance	3,528	1,977
Ending allowance balance individually evaluated for impairment	12	32
Ending allowance balance collectively evaluated for impairment	3,516	1,945
Total ending allowance balance	3,528	1,977
Loans individually evaluated for impairment	3,964	5,035
Loans collectively evaluated for impairment	384,869	312,102
Commercial Real Estate Portfolio Segment [Member] | ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	222	292
Charge-offs	0	0
Recoveries	0	0
Provision for loan losses	-85	56
Ending balance	137	236
Ending allowance balance	137	236
Total ending allowance balance	137	236
Loans	171,742	263,608
Residential Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,771	4,259
Provision for loan losses	-28	-29
Ending balance	3,787	4,234
Total ending allowance balance	3,787	4,234
Total Loans	636,062	609,225
Residential Portfolio Segment [Member] | Non ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,743	4,165
Charge-offs	-82	-20
Recoveries	30	90
Provision for loan losses	96	-66
Ending balance	3,787	4,169
Ending allowance balance individually evaluated for impairment	203	453
Ending allowance balance collectively evaluated for impairment	3,584	3,716
Total ending allowance balance	3,787	4,169
Loans individually evaluated for impairment	8,390	9,452
Loans collectively evaluated for impairment	594,514	539,306
Residential Portfolio Segment [Member] | ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	28	94
Charge-offs	0	0
Recoveries	0	0
Ending balance	0	65
Ending allowance balance	0	65
Total ending allowance balance	0	65
Loans	33,158	60,467
Consumer Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance			416	491
Ending balance	350	588	416	491
Total ending allowance balance	350	588	416	491
Total Loans	32,752	33,922
Consumer Portfolio Segment [Member] | Non ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	413	491
Charge-offs	-208	-171
Recoveries	83	76
Provision for loan losses	48	77
Ending balance	336	473
Ending allowance balance individually evaluated for impairment	2	3
Ending allowance balance collectively evaluated for impairment	334	470
Total ending allowance balance	336	473
Loans individually evaluated for impairment	231	249
Loans collectively evaluated for impairment	28,115	26,854
Consumer Portfolio Segment [Member] | ASC 310-30 [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3	0
Charge-offs	0	0
Recoveries	0	0
Provision for loan losses	11	-115
Ending balance	14	115
Ending allowance balance	14	115
Total ending allowance balance	14	115
Loans	$4,406	$6,819

Allowance_for_Loan_Losses_Narr

Allowance for Loan Losses - (Narrative) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	($1,453,000)	($1,769,000)
Non ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Allowance for Loan and Lease Losses Write-offs, Net	-200,000	-300,000
Provision for loan losses	-1,403,000	-1,823,000
ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-50,000	54,000
Commercial Portfolio Segment [Member] | Non ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-1,284,000	-1,880,000
Commercial Portfolio Segment [Member] | ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-20,000	84,000
Residential Portfolio Segment [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	28,000	29,000
Residential Portfolio Segment [Member] | Non ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-96,000	66,000
Consumer Loan [Member] | Non ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-48,000	-77,000
Consumer Loan [Member] | ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-11,000	115,000
Agriculture [Member] | Non ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-57,000	24,000
Agriculture [Member] | ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	-132,000	0
Commercial Real Estate Portfolio Segment [Member] | Non ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	82,000	44,000
Commercial Real Estate Portfolio Segment [Member] | ASC 310-30 [Member]
Allowance For Loan And Lease Losses [Line Items]
Provision for loan losses	$85,000	($56,000)

FDIC_Indemnification_Asset_Sum

FDIC Indemnification Asset - (Summary of Activity Related to FDIC Indemnification Asset) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
FDIC Indemnification Asset [Roll Forward]
Balance at beginning of period	$39,082	$64,447
Amortization	-7,670	-7,608
FDIC portion of (recoveries) charge-offs exceeding fair value marks	-4,900	-133
Change in carrying value of indemnification asset due to loss share submissions	1,342	-29
Balance at end of period	$27,854	$56,677

Other_Real_Estate_Owned_Summar

Other Real Estate Owned - (Summary of Activity in OREO Balances) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Other Real Estate [Roll Forward]
Balance	$29,120	$70,125
Transfers from loan portfolio, at fair value	498	236
Impairments	-470	-822
Sales	-7,202	-4,143
Gain on sale of OREO, net	1,471	587
Balance	$23,417	$65,983

FDIC_Indemnification_Asset_Nar

FDIC Indemnification Asset - (Narrative) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Banking and Thrift [Abstract]
Amortization	($7,670)	($7,608)
Decrease in carrying value of FDIC indemnification asset	-1,342	29
Payments/receipts to/from FDIC related to loss share assets	$1,300	$29

Other_Real_Estate_Owned_Narrat

Other Real Estate Owned - (Narrative) (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Banking and Thrift [Abstract]
OREO balance	$23,417,000	$29,120,000	$65,983,000	$70,125,000
Minority interests in OREO which are held by outside banks	8,100,000	8,100,000
Percentage covered by the loss sharing agreements with the FDIC	67.90%	63.40%
Amount covered by the loss sharing agreements with the FDIC	$15,900,000	$18,500,000

Borrowings_Narrative_Detail

Borrowings (Narrative) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Assets Sold under Agreements to Repurchase [Line Items]
Interest expense related to FHLB advances	$164
FHLB advances	$40,000	$40,000

Borrowings_Federal_Home_Loan_B

Borrowings (Federal Home Loan Bank, Advances) (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
December 31, 2014 balance
2016	$15,000
2018	10,000
2020	$15,000
Rate
2016	0.84%
2018	1.81%
2020	2.33%

Regulatory_Capital_Capital_Rat

Regulatory Capital - (Capital Ratio Requirements under Prompt Corrective Action or Other Regulatory Requirements) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Required to be considered well capitalized Ratio, leverage ratio	5.00%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	6.50%
Required to be considered well capitalized Ratio, risk-based capital ratio	8.00%
Required to be considered well capitalized Ratio, Total risk-based capital ratio	10.00%
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	14.10%	15.00%
Common equity risk-based ratio	26.30%
Risk-based capital Ratio	26.30%	28.90%
Total risk-based capital Ratio	27.10%	29.60%
Leverage Amount	$684,742	$712,222
Common equity risk-based amount	684,742
Risk-based capital amount	684,742	712,222
Total risk-based capital Amount	703,867	730,086
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	6.50%
Required to be considered well capitalized Ratio, risk-based capital ratio	8.00%	6.00%
Required to be considered well capitalized Ratio, Total risk-based capital ratio	10.00%	10.00%
Required to be considered well capitalized common equity capital amount	168,947
Required to be considered well capitalized risk-based capital Amount	207,935	147,796
Required to be considered well capitalized Total risk-based capital Amount	259,919	246,326
Required to be considered adequately capitalized Ratio, leverage ratio	4.00%	4.00%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	4.50%
Required to be considered adequately capitalized Ratio, risk-based capital ratio	6.00%	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	193,916	190,148
Required to be considered adequately capitalized common equity capital amount	116,963
Required to be considered adequately capitalized risk-based capital Amount	155,951	98,530
Required to be considered adequately capitalized Total risk-based capital Amount	207,935	197,061
NBH Bank, N.A. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Leverage Ratio	11.10%	12.10%
Common equity risk-based ratio	20.80%
Risk-based capital Ratio	20.80%	23.50%
Total risk-based capital Ratio	21.50%	24.20%
Leverage Amount	536,375	573,934
Common equity risk-based amount	536,375
Risk-based capital amount	536,375	573,934
Total risk-based capital Amount	555,499	591,799
Required to be considered well capitalized Ratio, leverage ratio	10.00%	10.00%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	6.50%
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	482,858	473,478
Required to be considered well capitalized common equity capital amount	167,683
Required to be considered well capitalized risk-based capital Amount	283,771	268,855
Required to be considered well capitalized Total risk-based capital Amount	309,568	293,297
Required to be considered adequately capitalized Ratio, leverage ratio	4.00%	4.00%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	4.50%
Required to be considered adequately capitalized Ratio, risk-based capital ratio	6.00%	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	193,143	189,391
Required to be considered adequately capitalized common equity capital amount	116,088
Required to be considered adequately capitalized risk-based capital Amount	154,784	97,766
Required to be considered adequately capitalized Total risk-based capital Amount	$206,379	$195,531

Regulatory_Capital_Narrative_D

Regulatory Capital - (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	6.50%	6.50%
Required to be considered well capitalized Ratio, risk-based capital ratio	8.00%	8.00%
Required to be considered well capitalized Ratio, Total risk-based capital ratio	10.00%	10.00%
Required to be considered well capitalized Ratio, leverage ratio	5.00%	5.00%
NBH Bank, N.A. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital Ratio	21.50%	21.50%	24.20%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	6.50%	6.50%
Required to be considered adequately capitalized Ratio, risk-based capital ratio	6.00%	6.00%	4.00%
Required to be considered adequately capitalized Ratio, Total risk-based capital ratio	8.00%	8.00%	8.00%
Required to be considered adequately capitalized Ratio, leverage ratio	4.00%	4.00%	4.00%
Required to be considered well capitalized Ratio, risk-based capital ratio	11.00%	11.00%	11.00%
Required to be considered well capitalized Ratio, Total risk-based capital ratio	12.00%	12.00%	12.00%
Required to be considered well capitalized Ratio, leverage ratio	10.00%	10.00%	10.00%
Approval from bank regulators to permanently reduce capital	$50
Cash dividends paid		$50
Minimum [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Risk-based capital computations	20.00%	20.00%

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
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Banking and Thrift [Abstract]
Clawback liability amortization	($368)	($328)
Clawback liability remeasurement	-1,107	-516
Reimbursement to FDIC for gain on sale of and income from covered OREO	-672	-918
Reimbursement to FDIC for recoveries	-8	-85
FDIC reimbursement of covered asset resolution costs	1,345	890
Total	($810)	($957)

Stockbased_Compensation_and_Em2

Stock-based Compensation and Employee Benefits - (Narrative) (Detail) (USD $)	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
NBH Holdings Corp. 2014 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	5,134,715
Grants After Plan Effective Date [Member] | NBH Holdings Corp. 2014 Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Reduction in Number of Shares for Every One Option or Stock Appreciation Right Granted	1
Share-based Compensation Arrangement by Share-based Payment Award, Reduction in Number of Shares for Every One Award Other Than An Option or Stock Appreciation Right Granted	3.25
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$0.10	$0.30
Unrecognized compensation expense	0.7
Unrecognized compensation cost, weighted-average period, years	0 years 10 months 17 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	0.5	0.4
Unrecognized compensation expense	$1.70
Unrecognized compensation cost, weighted-average period, years	0 years 11 months 13 days

Stockbased_Compensation_and_Em3

Stock-based Compensation and Employee Benefits - (Summary of Option Activity) (Detail) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding Options, beginning	3,597,111		3,503,403
Granted, Options	1,187
Forfeited, Options	-16,171
Surrendered, Options	0
Exercised, Options	0
Expired, Options	0
Outstanding Options, ending	3,582,127	3,597,111	3,503,403
Outstanding, Weighted Average Exercise Price, beginning	$19.90		$19.92
Granted, Weighted Average Exercise Price	$18.48
Forfeited, Weighted Average Exercise Price	$18.65
Surrendered, Weighted Average Exercise Price	$0
Exercised, Weighted Average Exercise Price	$0
Expired, Weighted Average Exercise Price	$0
Outstanding, Weighted Average Exercised Price, ending	$19.90	$19.90	$19.92
Outstanding, Weighted Average Remaining Contractual Term in Years, beginning	4 years 2 months 19 days	4 years 5 months 16 days
Outstanding, Weighted Average Remaining Contractual Term in Years, ending	4 years 2 months 19 days	4 years 5 months 16 days
Outstanding, Aggregate Intrinsic Value, beginning	$223,211
Outstanding, Aggregate Intrinsic Value, ending	83,653	223,211
Options fully vested and exercisable at September 30, 2014, Options	3,320,998
Options expected to vest, Options	254,057
Options fully vested and exercisable at September 30, 2014, Weighted Average Exercise Price	$19.99
Options expected to vest, Weighted Average Exercise Price	$18.89
Options fully vested and exercisable at September 30, 2014, weighted average remaining contractual term in years	3 years 10 months 17 days
Options expected to vest, Weighted Average Remaining Contractual Term in Years	8 years 2 months 16 days
Aggregate intrinsic Value of Options fully vested and exercisable at September 30, 2014	0
Options expected to vest, Aggregate Intrinsic Value	$68,271

Stockbased_Compensation_and_Em4

Stock-based Compensation and Employee Benefits - (Summary of Restricted Stock Activity) (Details) (Restricted Stock [Member], Common Class A [Member], USD $)	3 Months Ended
	Mar. 31, 2015
Restricted Stock [Member] | Common Class A [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)	955,398
Unvested Restricted Shares, Vested (in shares)	0
Unvested Restricted Shares, Granted (in shares)	1,187
Unvested Restricted Shares, Forfeited (in shares)	-2,648
Unvested Restricted Shares, Surrendered (in shares)	0
Unvested Restricted Shares, Ending (in shares)	953,937
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)	$15.16
Weighted Average Grant-Date Fair Value, Vested (in dollars per share)	$0
Weighted Average Grant-Date Fair Value, Granted (in dollars per share)	$18.48
Weighted Average Grant-Date Fair Value, Forfeited (in dollars per share)	$18.47
Weighted Average Grant-Date, Fair Value, Surrendered (in dollars per share)	$0
Weighted Average Grant-Date Fair Value, Ending (in dollars per share)	$15.15

Warrants_Narrative_Detail

Warrants (Narrative) (Detail) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Summary Activity In Gold Bullion [Line Items]
Outstanding warrants	830,750	830,750	830,750
Warrants granted, exercise price per share	$20	$20	$20
Warrant, contractual term (in years)	10 years
Fair value of the warrants	$2,900		$3,300
Gain (loss) from the change in fair value of warrant liability	($390)	($898)
Minimum [Member]
Summary Activity In Gold Bullion [Line Items]
Expiration dates of the warrants range	20-Oct-19
Maximum [Member]
Summary Activity In Gold Bullion [Line Items]
Expiration dates of the warrants range	30-Sep-20

Warrants_Schedule_of_Fair_Valu

Warrants (Schedule of Fair Value of Warrants Estimated Using Black-Scholes Option Pricing Model) (Detail) (Warrant [Member])	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Warrant Fair Value Black Scholes Method [Line Items]
Risk-free interest rate	1.35%	1.67%
Expected volatility	24.76%	24.18%
Dividend yield	1.06%	1.03%
Minimum [Member]
Warrant Fair Value Black Scholes Method [Line Items]
Expected term (years)	4 years	5 years
Maximum [Member]
Warrant Fair Value Black Scholes Method [Line Items]
Expected term (years)	5 years	6 years

Common_Stock_Narrative_Detail

Common Stock - (Narrative) (Detail) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Feb. 11, 2015	Oct. 21, 2014
Schedule Of Common Stock [Line Items]
Repurchase of shares	$38,145,000	$8,807,000
Shares outstanding	36,797,787		38,884,953
Restricted issued but not yet vested, shares	953,937		955,398
Common Class A [Member]
Schedule Of Common Stock [Line Items]
Shares outstanding	36,412,058		38,017,179
Common Class B [Member]
Schedule Of Common Stock [Line Items]
Shares outstanding	385,729		867,774
Board Authorized Share Repurchase Programs [Member]
Schedule Of Common Stock [Line Items]
Stock repurchase program, authorized amount				50,000,000	50,000,000
Shares repurchased (shares)	2,087,166
Repurchase of shares	$37,700,000
Shares repurchased (weighted average cost per share)	$18.03

Income_Per_Share_Narrative_Det

Income Per Share - (Narrative) (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Earnings Per Share [Abstract]
Shares outstanding	36,797,787	44,486,467
Outstanding stock options to purchase common stock	3,582,127	3,503,403	3,597,111
Outstanding stock options to purchase common stock, per share	$19.90	$19.92	$19.90
Outstanding warrants	830,750	830,750	830,750
Warrants granted, exercise price per share	$20	$20	$20
Restricted shares outstanding	953,937	1,021,127

Income_Per_Share_Schedule_of_C

Income Per Share - (Schedule of Computation of Basic and Diluted Income Per Share) (Detail) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Distributed earnings	$1,908	$2,276
Undistributed earnings (distributions in excess of earnings)	-662	-845
Net income	1,246	1,431
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	-10	-5
Income available to common stockholders (numerator)	$1,236	$1,426
Weighted average common shares outstanding (denominator)	38,028,506	44,819,644
Weighted average shares outstanding for diluted earnings per common share	38,028,612	44,863,138
Income per share—basic (in dollars per share)	$0.03	$0.03
Income per share—diluted (in dollars per share)	$0.03	$0.03
Equity Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive Convertible Securities	106	35,827
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive Convertible Securities	0	7,667

Derivatives_FV_of_Derivatives_

Derivatives - (FV of Derivatives on the Balance Sheet) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset Derivatives	$38	$10
Liability Derivatives	5,386	3,206
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset Derivatives	2,018	1,418
Liability Derivatives	2,164	1,522
Other assets [Member] | Interest rate products [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset Derivatives	38	10
Other assets [Member] | Interest rate products [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset Derivatives	2,018	1,418
Other liabilities [Member] | Interest rate products [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability Derivatives	5,386	3,206
Other liabilities [Member] | Interest rate products [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability Derivatives	$2,164	$1,522

Derivatives_Narrative_Details

Derivatives - (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
			Swap
Derivative [Line Items]
Termination value of derivatives in net liability position	$8,200,000
Collateral Already Posted, Aggregate Fair Value	9,200,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Number of interest rate swaps held	13		11
Notional amount	42,700,000		35,900,000
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) related to hedge ineffectiveness	-140,000	-73,000
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Number of interest rate swaps held	16		11
Notional amount	$131,400,000		$68,800,000

Derivatives_Derivatives_on_the

Derivatives - (Derivatives on the Income Statement) (Details) (Interest rate products [Member], Fair Value Hedging [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	($2,152)	($614)
Amount of Gain or (Loss) Recognized in Income on Hedged Item	2,013	541
Designated as Hedging Instrument [Member] | Interest income [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	-2,152	-614
Amount of Gain or (Loss) Recognized in Income on Hedged Item	2,013	541
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	-39	-14
Not Designated as Hedging Instrument [Member] | Other Non-Interest income [Member]
Derivative [Line Items]
Amount of Gain or (Loss) Recognized in Income on Derivative	($39)	($14)

Commitments_and_Contingencies_1

Commitments and Contingencies (Narrative) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Commitment And Contingencies [Line Items]
Loan commitments	$468,600,000	$485,500,000
Standby Letters of Credit [Member]
Commitment And Contingencies [Line Items]
Standby letters of credit	$10,374,000	$9,965,000

Commitments_and_Contingencies_2

Commitments and Contingencies (Schedule of Total Unfunded Commitments) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	$5,826	$7,890
Unfunded commitment not covered under the FDIC loss sharing agreement	473,132	487,567
Total Unfunded Loan Commitments	478,958	495,457
Credit Card Lines of Credit [Member]
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	0	0
Unfunded commitment not covered under the FDIC loss sharing agreement	17,717	18,065
Total Unfunded Loan Commitments	17,717	18,065
Unfunded Commitments Under Lines of Credit [Member]
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	5,581	7,645
Unfunded commitment not covered under the FDIC loss sharing agreement	220,107	215,305
Total Unfunded Loan Commitments	225,688	222,950
Commercial and Standby Letters of Credit [Member]
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	234	234
Unfunded commitment not covered under the FDIC loss sharing agreement	10,140	9,731
Commitments to Fund Loans [Member] | Residential [Member]
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	0	0
Unfunded commitment not covered under the FDIC loss sharing agreement	2,669	1,683
Total Unfunded Loan Commitments	2,669	1,683
Commitments to Fund Loans [Member] | Commercial and Commercial Real Estate [Member]
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	11	11
Unfunded commitment not covered under the FDIC loss sharing agreement	191,008	202,593
Total Unfunded Loan Commitments	191,019	202,604
Commitments to Fund Loans [Member] | Construction and Land Development [Member]
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	0	0
Unfunded commitment not covered under the FDIC loss sharing agreement	27,079	35,814
Total Unfunded Loan Commitments	27,079	35,814
Commitments to Fund Loans [Member] | Consumer [Member]
Commitment And Contingencies [Line Items]
Unfunded commitment covered under the FDIC loss sharing agreement	0	0
Unfunded commitment not covered under the FDIC loss sharing agreement	4,412	4,376
Total Unfunded Loan Commitments	4,412	4,376
Standby Letters of Credit [Member]
Commitment And Contingencies [Line Items]
Standby letters of credit	$10,374	$9,965

Fair_Value_Measurements_Tables1

Fair Value Measurements - (Tables of Financial Instruments Measured At Fair Value on Recurring Basis) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	$1,415,470	$1,480,642
Total liabilities at fair value	48,301	44,394
Other Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	419	419
Derivative [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	2,056	1,428
Total liabilities at fair value	7,550	4,728
Warrant Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	2,938	3,328
Clawback Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	37,813	36,338
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	385,236	404,215
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	1,027,759	1,074,580
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
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] | Derivative [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
Total liabilities 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] | 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	1,415,051	1,480,223
Total liabilities at fair value	7,550	4,728
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] | Derivative [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	2,056	1,428
Total liabilities at fair value	7,550	4,728
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] | 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	385,236	404,215
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	1,027,759	1,074,580
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	40,751	39,666
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] | Derivative [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value	0	0
Total liabilities at fair value	0	0
Level 3 [Member] | Warrant Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	2,938	3,328
Level 3 [Member] | Clawback Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	37,813	36,338
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 $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Warrant [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$3,328	$6,281
Change in value	-390	-898
Amortization	0	0
Net change in Level 3	-390	-898
Ending Balance	2,938	5,383
Clawback Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	36,338	32,465
Change in value	1,107	516
Amortization	368	328
Net change in Level 3	1,475	844
Ending Balance	$37,813	$33,309

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of comparable companies for expected volatility	8
Measuring period for payments to the FDIC	45 days
Number of Loans measured	8
Nonrecurring Loans Reserves	$900,000
Additions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of Loans measured	4
Nonrecurring Loans Reserves	700,000
Nonrecurring Loans Carrying value	1,000,000
Eliminations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of Loans measured	4
Nonrecurring Loans Reserves	100,000
FDIC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate Owned Impairments Covered by the FDIC	200,000	600,000
Percentage of OREO impairments covered by the FDIC	44.50%	69.60%
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses from change in fair value	-470,000	-822,000
Collateral Dependent Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses from change in fair value	($146,000)	($465,000)

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 $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$23,417	$65,983
Losses From Fair Value Changes	470	822
Impaired loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	30,898	33,103
Losses From Fair Value Changes	146	465
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	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	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	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	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	23,417	65,983
Level 3 [Member] | Impaired loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Nonrecurring	$30,898	$33,103

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 $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets at fair value	1,415,470,000	$1,480,642,000
Total liabilities at fair value	48,301,000	44,394,000
Other Securities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total assets at fair value	419,000
Impaired loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total liabilities at fair value	30,898,000
Clawback Liability [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total liabilities at fair value	37,813,000
Warrant Liability [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Total liabilities at fair value	2,938,000
Discounted Cash Flows [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate	4.00%
Minimum [Member] | Appraised value [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Appraised values Discount rate	0.00%
Minimum [Member] | Contractually Defined [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Intrinsic loss estimates	323,300,000
Minimum [Member] | Black-Scholes [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Volatility	18.00%
Maximum [Member] | Appraised value [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Appraised values Discount rate	25.00%
Maximum [Member] | Contractually Defined [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Intrinsic loss estimates	405,000,000
Maximum [Member] | Black-Scholes [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Volatility	30.00%

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - (Schedule of Fair Value of Financial Instruments) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
ASSETS:
Cash and cash equivalents	$490,104	$256,979	$197,815	$189,460
Investment securities available-for-sale (at fair value)	1,413,414	1,479,214
Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	503,610	530,590
Loans held-for-sale	4,935	5,146
LIABILITIES:
Time deposits	1,324,661	1,357,051
Securities sold under agreements to repurchase	284,161	133,552
Advances from Federal Home Loan Banks	40,000	40,000
Due to FDIC	37,813	42,011
Warrant liability	2,900	3,300
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)	385,236	404,215
Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	400,408	422,622
Other Residential MBS Issued or Guaranteed by U.S. Government Agencies or Sponsored Enterprises [Member]
ASSETS:
Investment securities available-for-sale (at fair value)	1,027,759	1,074,580
Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	103,202	107,968
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	490,104	256,979
Carrying Amount [Member] | Level 2 [Member]
ASSETS:
Capital stock of FHLB	7,361	7,595
Capital stock of FRB	19,689	19,450
Loans held-for-sale	4,935	5,146
Accrued interest receivable	12,070	11,465
Derivative asset	2,056	1,428
LIABILITIES:
Deposit transaction accounts	2,507,801	2,409,137
Time deposits	1,324,661	1,357,051
Securities sold under agreements to repurchase	284,161	133,552
Advances from Federal Home Loan Banks	40,000	40,000
Accrued interest payable	3,804	3,608
Derivative liability	7,550	4,728
Carrying Amount [Member] | Level 3 [Member]
ASSETS:
Loans receivable, net	2,197,396	2,144,796
LIABILITIES:
Due to FDIC	37,813	42,011
Warrant liability	2,938	3,328
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)	385,236	404,215
Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	400,408	422,622
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)	1,027,759	1,074,580
Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	103,202	107,968
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	490,104	256,979
Estimated Fair Value [Member] | Level 2 [Member]
ASSETS:
Capital stock of FHLB	7,361	7,595
Capital stock of FRB	19,689	19,450
Loans held-for-sale	4,935	5,146
Accrued interest receivable	12,070	11,465
Derivative asset	2,056	1,428
LIABILITIES:
Deposit transaction accounts	2,507,801	2,409,137
Time deposits	1,325,585	1,357,885
Securities sold under agreements to repurchase	284,161	133,552
Advances from Federal Home Loan Banks	40,790	40,465
Accrued interest payable	3,804	3,608
Derivative liability	7,550	4,728
Estimated Fair Value [Member] | Level 3 [Member]
ASSETS:
Loans receivable, net	2,255,644	2,193,222
LIABILITIES:
Due to FDIC	37,813	42,011
Warrant liability	2,938	3,328
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)	385,236	404,215
Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	408,251	428,323
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)	1,027,759	1,074,580
Mortgage-backed securities—residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises held-to-maturity	102,552	106,314
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)	3 Months Ended
	Mar. 31, 2015
Fair Value Of Financial Instruments [Abstract]
Residential mortgage loans held for sale period	45 days