CVB Financial (CVBF) 10-Q 11 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document And Entity Information [Abstract]
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	CVBF
Entity Registrant Name	CVB FINANCIAL CORP
Entity Central Index Key	354647
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		106,256,535

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Assets
Cash and due from banks	$112,336	$95,030
Interest-earning balances due from Federal Reserve	289,036	10,738
Total cash and cash equivalents	401,372	105,768
Interest-earning balances due from depository institutions	25,873	27,118
Investment securities available-for-sale, at fair value (with amortized cost of $2,954,443 at March 31, 2015, and $3,083,582 at December 31, 2014)	3,028,289	3,137,158
Investment securities held-to-maturity	1,464	1,528
Investment in stock of Federal Home Loan Bank (FHLB)	25,338	25,338
Loans and lease finance receivables	3,716,023	3,817,067
Allowance for loan losses	-60,709	-59,825
Net loans and lease finance receivables	3,655,314	3,757,242
Premises and equipment, net	32,628	33,591
Bank owned life insurance	127,557	126,927
Accrued interest receivable	22,872	23,194
Intangibles	2,946	3,214
Goodwill	74,244	74,244
FDIC loss sharing asset	0	299
Other real estate owned	7,122	5,637
Income taxes	14,848	31,461
Other assets	23,084	25,201
Total assets	7,442,951	7,377,920
Deposits:
Noninterest-bearing	3,126,928	2,866,365
Interest-bearing	2,770,848	2,738,293
Total deposits	5,897,776	5,604,658
Customer repurchase agreements	560,352	563,627
FHLB advances	0	199,479
Other borrowings	0	46,000
Accrued interest payable	306	1,161
Deferred compensation	10,988	10,291
Junior subordinated debentures	25,774	25,774
Payable for securities purchased	2,350	0
Other liabilities	48,287	48,821
Total liabilities	6,545,833	6,499,811
Commitments and Contingencies
Stockholders' Equity
Common stock, authorized, 225,000,000 shares without par; issued and outstanding 106,246,910 at March 31, 2015, and 105,893,216 at December 31, 2014	499,382	495,220
Retained earnings	354,905	351,814
Accumulated other comprehensive income, net of tax	42,831	31,075
Total stockholders' equity	897,118	878,109
Total liabilities and stockholders' equity	$7,442,951	$7,377,920

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Amortized cost	$2,954,443	$3,083,582
Common stock, par value	$0	$0
Common stock, authorized	225,000,000	225,000,000
Common stock, shares issued	106,246,910	105,893,216
Common stock, shares outstanding	106,246,910	105,893,216

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Earnings and Comprehensive Income (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Interest income:
Loans and leases, including fees	$45,542	$44,656
Investment securities:
Taxable	12,961	10,279
Tax-advantaged	5,011	5,278
Total investment income	17,972	15,557
Dividends from FHLB stock	469	604
Federal funds sold	142	124
Interest-earning deposits with other institutions	55	121
Total interest income	64,180	61,062
Interest expense:
Deposits	1,293	1,186
Borrowings	1,773	2,830
Junior subordinated debentures	105	104
Total interest expense	3,171	4,120
Net interest income before provision for loan losses	61,009	56,942
Provision for (recapture of) loan losses	0	-7,500
Net interest income after provision for loan losses	61,009	64,442
Noninterest income:
Service charges on deposit accounts	3,961	3,828
Trust and investment services	2,151	1,925
Bankcard services	733	778
BOLI income	649	638
Gain on sale of loans held-for-sale	0	5,330
Decrease in FDIC loss sharing asset, net	-390	-1,707
Gain on OREO, net	124	5
Other	783	701
Total noninterest income	8,011	11,498
Noninterest expense:
Salaries and employee benefits	19,295	19,417
Occupancy and equipment	3,652	3,725
Professional services	1,153	1,791
Software licenses and maintenance	1,030	1,065
Promotion	1,327	1,266
Provision for unfunded loan commitments	-500	0
Amortization of intangible assets	268	122
Debt termination expense	13,870	0
OREO expense	84	25
Other	4,293	3,746
Total noninterest expense	44,472	31,157
Earnings before income taxes	24,548	44,783
Income taxes	8,715	16,122
Net earnings	15,833	28,661
Other comprehensive income:
Unrealized gain on securities arising during the period	20,270	24,781
Less: Reclassification adjustment for net gain on securities included in net income	0	0
Other comprehensive income, before tax	20,270	24,781
Less: Income tax expense related to items of other comprehensive income	-8,514	-10,407
Other comprehensive income, net of tax	11,756	14,374
Comprehensive income	$27,589	$43,035
Basic earnings per common share	$0.15	$0.27
Diluted earnings per common share	$0.15	$0.27
Cash dividends declared per common share	$0.12	$0.10

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Stockholders' Equity (USD $)	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
In Thousands
Beginning balance at Dec. 31, 2013	$771,887	$491,068	$290,149	($9,330)
Beginning balance, shares at Dec. 31, 2013		105,370
Repurchase of common stock	-32	-32
Repurchase of common stock, shares		-2
Exercise of stock options	3,684	3,684
Exercise of stock options, shares		334
Tax benefit from exercise of stock options	559	559
Shares issued pursuant to stock-based compensation plan	656	656
Shares issued pursuant to stock-based compensation plan, shares		310
Cash dividends declared on common stock	-10,608		-10,608
Net earnings	28,661		28,661
Other comprehensive income	14,374			14,374
Ending balance at Mar. 31, 2014	809,181	495,935	308,202	5,044
Ending balance, shares at Mar. 31, 2014		106,012
Beginning balance at Dec. 31, 2014	878,109	495,220	351,814	31,075
Beginning balance, shares at Dec. 31, 2014		105,893
Repurchase of common stock	-497	-497
Repurchase of common stock, shares		-32
Exercise of stock options	3,313	3,313
Exercise of stock options, shares		306
Tax benefit from exercise of stock options	614	614
Shares issued pursuant to stock-based compensation plan	732	732
Shares issued pursuant to stock-based compensation plan, shares		80
Cash dividends declared on common stock	-12,742		-12,742
Net earnings	15,833		15,833
Other comprehensive income	11,756			11,756
Ending balance at Mar. 31, 2015	$897,118	$499,382	$354,905	$42,831
Ending balance, shares at Mar. 31, 2015		106,247

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Stockholders' Equity [Abstract]
Cash dividends per common share	$0.12	$0.10

Condensed_Consolidated_Stateme3

Condensed 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
Interest and dividends received	$68,591	$63,935
Service charges and other fees received	6,848	7,237
Interest paid	-3,981	-4,080
Net cash paid to vendors, employees and others	-43,608	-37,955
Income taxes paid	0	0
Proceeds from (payments to) FDIC loss share agreement	265	-185
Net cash provided by operating activities	28,115	28,952
Cash Flows from Investing Activities
Proceeds from redemption of FHLB stock	0	6,771
Proceeds from maturity of interest-earning balances from depository institutions	1,245	0
Proceeds from repayment of investment securities	94,479	65,093
Proceeds from maturity of investment securities	34,014	39,768
Purchases of investment securities	-1,967	-99,689
Net decrease in loan and lease finance receivables	101,774	157,719
Purchase of premises and equipment	-157	-301
Proceeds from sales of other real estate owned	1,418	0
Net cash provided by investing activities	230,806	169,361
Cash Flows from Financing Activities
Net increase in transaction deposits	322,642	237,238
Net decrease in time deposits	-29,524	-17,083
Repayment of FHLB advances	-200,000	0
Net decrease in other borrowings	-46,000	-69,000
Net decrease in customer repurchase agreements	-3,275	-16,449
Cash dividends on common stock	-10,590	-10,537
Repurchase of common stock	-497	-32
Proceeds from exercise of stock options	3,313	3,684
Tax benefit related to exercise of stock options	614	559
Net cash provided by financing activities	36,683	128,380
Net increase in cash and cash equivalents	295,604	326,693
Cash and cash equivalents, beginning of period	105,768	94,693
Cash and cash equivalents, end of period	401,372	421,386
Reconciliation of Net Earnings to Net Cash Provided by Operating Activities
Net earnings	15,833	28,661
Adjustments to reconcile net earnings to net cash provided by operating activities:
Gain on sale of loans held-for-sale	0	-5,330
Gain on sale of investment securities	0	0
(Gain) loss on sale of premises and equipment, net	-1	204
Gain on sale of other real estate owned	-112	0
Amortization of capitalized prepayment penalty on borrowings	521	68
Increase in bank owned life insurance	-630	-622
Net amortization of premiums and discounts on investment securities	5,025	5,094
Accretion of SJB discount	-980	-1,707
Provision for loan losses	0	-7,500
Provision for unfunded loan commitments	-500	0
Valuation adjustment on other real estate owned	33	0
Change in FDIC loss sharing asset	299	1,707
Proceeds from (payments to) FDIC loss share agreement	265	-185
Stock-based compensation	732	656
Depreciation and amortization, net	-271	354
Change in accrued interest receivable	322	276
Change in accrued interest payable	-855	-28
Change in other assets and liabilities	8,434	7,304
Total adjustments	12,282	291
Net cash provided by operating activities	28,115	28,952
Net cash provided by investing activities	230,806	169,361
Net cash provided by financing activities	36,683	128,380
Net increase in cash and cash equivalents	295,604	326,693
Supplemental Disclosure of Noncash Investing Activities
Securities purchased and not settled	2,350	75,392
Transfer of loans to other real estate owned	$2,824	$0

Business

Business	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Business	1. BUSINESS
	The condensed consolidated financial statements include the accounts of CVB Financial Corp. (referred to herein on an unconsolidated basis as “CVB” and on a consolidated basis as “we,” “our” or the “Company”) and its wholly owned subsidiaries: Citizens Business Bank (the “Bank” or “CBB”) after elimination of all intercompany transactions and balances. The Company has one inactive subsidiary, Chino Valley Bancorp. The Company is also the common stockholder of CVB Statutory Trust III. CVB Statutory Trust III was created in January 2006 to issue trust preferred securities in order to raise capital for the Company. In accordance with ASC 810 Consolidation, this trust does not meet the criteria for consolidation.
	The Company’s primary operations are related to traditional banking activities, including the acceptance of deposits and the lending and investing of money through the operations of the Bank. The Bank also provides automobile and equipment leasing to customers through its Citizens Financial Services Group and trust and investment-related services to customers through its CitizensTrust Division. The Bank’s customers consist primarily of small to mid-sized businesses and individuals located in San Bernardino County, Riverside County, Los Angeles County, Orange County, Ventura County, San Diego County, Madera County, Fresno County, Tulare County and Kern County, California. The Bank operates 40 Business Financial Centers, seven Commercial Banking Centers, and three trust office locations. The Company is headquartered in the city of Ontario, California.

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	2. BASIS OF PRESENTATION
	The accompanying unaudited condensed consolidated financial statements and notes thereto have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) for Form 10-Q and conform to practices within the banking industry and include all of the information and disclosures required by accounting principles generally accepted in the United States of America (“GAAP”) for interim financial reporting. The accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments), which are necessary for a fair presentation of financial results for the interim periods presented. The results of operations for the three months ended March 31, 2015 are not necessarily indicative of the results for the full year. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements, accounting policies and financial notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2014, filed with the SEC. A summary of the significant accounting policies consistently applied in the preparation of the accompanying unaudited condensed consolidated financial statements follows.
	Reclassification – Certain amounts in the prior periods’ condensed consolidated financial statements and related footnote disclosures have been reclassified to conform to the current presentation with no impact on previously reported net income or stockholders’ equity.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Except as discussed below, our accounting policies are described in Note 3—Summary of Significant Accounting Policies, of our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2014 as filed with the SEC (“Form 10-K”).
	Use of Estimates in the Preparation of Financial Statements — The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. A material estimate that is particularly susceptible to significant change in the near term relates to the determination of the allowance for loan losses. Other significant estimates which may be subject to change include fair value determinations and disclosures, impairment of investments, goodwill, loans, as well as valuation of deferred tax assets, other intangibles and OREO.
	Recent Accounting Pronouncements— In February 2015, the FASB issued ASU No. 2015-02, “Consolidation (Topic 810): Amendments to the Consolidation Analysis”. The new guidance reduces the number of consolidation models from four to two as well as simplifies the FASB Accounting Standards Codification and improves GAAP by placing more of an emphasis on risk of loss when determining a controlling financial interest, reducing the frequency of the application of related party guidance when determining a controlling financial interest in a variable interest entity (VIE) and changing the consolidation conclusions for public and private companies in several industries that typically make use of VIEs. ASU 2015-02 will be effective for the first interim period within annual reporting periods beginning after December 15, 2016. Early adoption is permitted. The adoption of this guidance is not expected to have a material impact on the Company’s consolidated financial statements.

Investment_Securities

Investment Securities	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investment Securities	4. INVESTMENT SECURITIES
	The amortized cost and estimated fair value of investment securities are summarized below. The majority of securities held are publicly traded, and the estimated fair values were obtained from an independent pricing service based upon market quotes.
		March 31, 2015
		Amortized		Gross		Gross			Fair Value		Total
		Cost		Unrealized		Unrealized					Percent
				Holding		Holding Loss
				Gain
		(Dollars in thousands)
	Investment securities available-for-sale:
	Government agency	$	334,025	$	140	$	(4,299	)	$	329,866		10.89	%
	Residential mortgage-backed securities		1,807,036		49,360		(1,242	)		1,855,154		61.26	%
	CMOs / REMICs - residential		279,918		8,406		(80	)		288,244		9.52	%
	Municipal bonds		528,464		21,910		(530	)		549,844		18.16	%
	Other securities		5,000		181		—			5,181		0.17	%
	Total	$	2,954,443	$	79,997	$	(6,151	)	$	3,028,289		100	%
		December 31, 2014
		Amortized		Gross		Gross			Fair Value		Total
		Cost		Unrealized		Unrealized					Percent
				Holding		Holding
				Gain		Loss
		(Dollars in thousands)
	Investment securities available-for-sale:
	Government agency	$	339,071	$	—	$	(8,228	)	$	330,843		10.55	%
	Residential mortgage-backed securities		1,884,370		36,154		(3,028	)		1,917,496		61.12	%
	CMOs / REMICs - residential		297,318		7,050		(277	)		304,091		9.69	%
	Municipal bonds		557,823		22,463		(645	)		579,641		18.48	%
	Other securities		5,000		87		—			5,087		0.16	%
	Total	$	3,083,582	$	65,754	$	(12,178	)	$	3,137,158		100	%
	Approximately 82% of the available-for-sale portfolio at March 31, 2015 represents securities issued by the U.S government or U.S. government-sponsored enterprises, with the implied guarantee of payment of principal and interest. All non-agency available-for-sale CMO/REMIC issues held are rated investment grade or better by either Standard & Poor’s or Moody’s, as of March 31, 2015 and December 31, 2014. The Bank had $304,000 in CMOs/REMICs backed by whole loans issued by private-label companies (nongovernment sponsored).
	The tables below show the Company’s investment securities’ gross unrealized losses and fair value by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2015 and December 31, 2014. Management has reviewed individual securities to determine whether a decline in fair value below the amortized cost basis is other-than temporary.
		March 31, 2015
		Less Than 12 Months				12 Months or Longer					Total
		Fair Value		Gross		Fair Value			Gross		Fair Value			Gross
				Unrealized					Unrealized					Unrealized
				Holding					Holding					Holding
				Losses					Losses					Losses
		(Dollars in thousands)
	Available-for-sale:
	Government agency	$	14,558	$	3	$	289,548		$	4,296	$	304,106		$	4,299
	Residential mortgage-backed securities		—		—		128,416			1,242		128,416			1,242
	CMOs / REMICs - residential		—		—		6,679			80		6,679			80
	Municipal bonds		4,152		47		23,917			483		28,069			530
	Other securities		—		—		—			—		—			—
	Total	$	18,710	$	50	$	448,560		$	6,101	$	467,270		$	6,151
		December 31, 2014
		Less Than 12 Months				12 Months or Longer					Total
		Fair Value		Gross		Fair Value			Gross		Fair Value			Gross
				Unrealized					Unrealized					Unrealized
				Holding					Holding					Holding
				Losses					Losses					Losses
		(Dollars in thousands)
	Available-for-sale:
	Government agency	$	22,224	$	28	$	307,873		$	8,200	$	330,097		$	8,228
	Residential mortgage-backed securities		19,636		4		145,681			3,024		165,317			3,028
	CMOs / REMICs - residential		—		—		31,143			277		31,143			277
	Municipal bonds		1,953		23		24,812			622		26,765			645
	Other securities		—		—		—			—		—			—
	Total	$	43,813	$	55	$	509,509		$	12,123	$	553,322		$	12,178
	The following summarizes our analysis of these securities and the unrealized losses. This assessment was based on the following factors: i) the length of the time and the extent to which the fair value has been less than amortized cost; ii) adverse condition specifically related to the security, an industry, or a geographic area and whether or not the Company expects to recover the entire amortized cost, iii) historical and implied volatility of the fair value of the security; iv) the payment structure of the security and the likelihood of the issuer being able to make payments in the future; v) failure of the issuer of the security to make scheduled interest or principal payments, vi) any changes to the rating of the security by a rating agency, and vii) recoveries or additional declines in fair value subsequent to the balance sheet date.
	CMO Held-to-Maturity — The Company has one investment security classified as held-to-maturity. This security was issued by Countrywide Financial and is collateralized by Alt-A (limited documentation) mortgages. The mortgages are primarily fixed-rate, 30-year loans, originated in early 2006 with average FICO scores of 715 and an average LTV of 71% at origination. The security was a senior security in the securitization, was rated triple AAA at origination and was supported by subordinate securities. This security is classified as held-to-maturity as the Bank has both the intent and ability to hold this debt security to maturity. The Bank acquired this security in February 2008 at a price of 98.25%. The significant decline in the fair value of the security first appeared in August 2008 at the time the crisis in the financial markets occurred and the market for securities collateralized by Alt-A mortgages diminished.
	As of March 31, 2015, the unrealized loss on this security was zero and the current fair value on the security was 78.76% of the current par value. This Alt-A bond, with a book value of $1.5 million as of March 31, 2015, has $1.9 million in net impairment losses to date. These losses have been recorded as a reduction to noninterest income. The security is rated non-investment grade. We evaluated the security for an other-than-temporary decline in fair value as of March 31, 2015. The key assumptions include default rates, loss severities and prepayment rates. There were no changes in credit related other-than temporary impairment (“OTTI”) recognized in earnings for the quarter ended March 31, 2015 and 2014.
	Government Agency & Government-Sponsored Enterprise— The government agency bonds are backed by the full faith and credit of agencies of the U.S. Government. While the Government-Sponsored Enterprise bonds are not expressly guaranteed by the U.S. Government, they are currently being supported by the U.S. Government under a conservatorship arrangement with the Government-Sponsored Enterprises. As of March 31, 2015, approximately $140.9 million in U.S. government agency bonds are callable. These securities are bullet securities, that is, they have a defined maturity date on which the principal is paid. The contractual term of these investments provides that the Company will receive the face value of the bond at maturity which will equal the amortized cost of the bond. Interest is received throughout the life of the security.
	Mortgage-Backed Securities and CMOs/REMICs— Almost all of the Company’s available-for-sale mortgage-backed and CMOs/REMICs securities are issued by Government Agencies or Government-Sponsored Enterprises such as Ginnie Mae, Fannie Mae and Freddie Mac. These securities are collateralized or backed by the underlying residential mortgages. All mortgage-backed securities are considered to be rated investment grade with a weighted average life of approximately 3.8 years. Of the total MBS/CMO, 99.99% have the implied guarantee of U.S. Government-Sponsored Agencies and Enterprises. The remaining .01% are issued by banks. Accordingly, it is expected the securities would not be settled at a price less than the amortized cost of the bonds.
	Municipal Bonds—The majority of the Company’s municipal bonds, with a weighted-average life of approximately 8.4 years, are insured by the largest bond insurance companies. The Company diversifies its holdings by owning selections of securities from different issuers and by holding securities from geographically diversified municipal issuers, thus reducing the Company’s exposure to any single adverse event. The decline in fair value is attributable to the changes in interest rates and not credit quality. Since the Company does not intend to sell the investments and it is not more likely than not that the Company will be required to sell the investments before recovery of their amortized costs, these investments are not considered other than temporarily impaired at March 31, 2015.
On an ongoing basis, we monitor the quality of our municipal bond portfolio in light of the current financial problems exhibited by certain monoline insurance companies. Many of the securities that would not be rated without insurance are pre-refunded and/or are general obligation bonds. We continue to monitor municipalities, which includes a review of the respective municipalities’ audited financial statements to determine whether there are any audit or performance issues. We use outside brokers to assist us in these analyses. Based on our monitoring of the municipal marketplace, to our knowledge, none of the municipalities are exhibiting financial problems that would lead us to believe that there is OTTI for any given security.
At March 31, 2015 and December 31, 2014, investment securities having a carrying value of approximately $2.99 billion and $3.11 billion, respectively, were pledged to secure public deposits, short and long-term borrowings, and for other purposes as required or permitted by law.
The amortized cost and fair value of debt securities at March 31, 2015, by contractual maturity, are shown in the table below. Although mortgage-backed securities and CMOs/REMICs have contractual maturities through 2043, expected maturities will differ from contractual maturities because borrowers may have the right to prepay such obligations without penalty. Mortgage-backed securities and CMOs/REMICs are included in maturity categories based upon estimated prepayment speeds.
	March 31, 2015
	Amortized		Fair
	Cost		Value
	(Dollars in thousands)
Available-for-sale:
Due in one year or less	$	160,730	$	164,801
Due after one year through five years		1,946,053		2,009,028
Due after five years through ten years		727,902		730,599
Due after ten years		119,758		123,861
Total	$	2,954,443	$	3,028,289
The investment in FHLB stock is periodically evaluated for impairment based on, among other things, the capital adequacy of the FHLB and its overall financial condition. No impairment losses have been recorded through March 31, 2015.

Acquired_SJB_Assets_and_FDIC_L

Acquired SJB Assets and FDIC Loss Sharing Asset	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
Acquired SJB Assets and FDIC Loss Sharing Asset	5. ACQUIRED SJB ASSETS AND FDIC LOSS SHARING ASSET
	FDIC Assisted Acquisition
	On October 16, 2009, the Bank acquired San Joaquin Bank (“SJB”) and entered into loss sharing agreements with the Federal Deposit Insurance Corporation (“FDIC”) that is more fully discussed in Note 3—Summary of Significant Accounting Policies, included in our Annual Report on Form 10-K for the year ended December 31, 2014. The acquisition has been accounted for under the purchase method of accounting. The assets and liabilities were recorded at their estimated fair values as of the October 16, 2009 acquisition date. The acquired loans were accounted for as Purchase Credit Impaired (“PCI”) loans. The application of the purchase method of accounting resulted in an after-tax gain of $12.3 million which was included in 2009 earnings. The gain is the negative goodwill resulting from the acquired assets and liabilities recognized at fair value.
	At March 31, 2015, the remaining discount associated with the PCI loans approximated $6.6 million. Based on the Company’s regular forecast of expected cash flows from these loans, approximately $4.4 million of the related discount is expected to accrete into interest income over the remaining average lives of the respective pools and individual loans, which approximates 3.7 years and 0.8 years, respectively. The loss sharing agreement for commercial loans expired October 16, 2014. The following table provides a summary of PCI loans and lease finance receivables by type and their credit quality indicators for the periods indicated.
		March 31, 2015			December 31, 2014
		(Dollars in thousands)
	Commercial and industrial	$	13,988		$	14,605
	SBA		1,073			1,110
	Real estate:
	Commercial real estate		102,445			109,350
	Construction		—			—
	SFR mortgage		197			205
	Dairy & livestock and agribusiness		330			4,890
	Municipal lease finance receivables		—			—
	Consumer and other loans		2,997			3,336
	Gross PCI loans		121,030			133,496
	Less: Purchase accounting discount		(6,612	)		(7,129	)
	Gross PCI loans, net of discount		114,418			126,367
	Less: Allowance for PCI loans losses		—			—
	Net PCI loans	$	114,418		$	126,367
	Credit Quality Indicators
	The following table summarizes PCI loans by internal risk ratings for the periods indicated.
		March 31, 2015			December 31, 2014
		(Dollars in thousands)
	Pass	$	25,483		$	26,706
	Watch list		69,635			77,371
	Special mention		7,148			8,203
	Substandard		18,764			21,216
	Doubtful & loss		—			—
	Total PCI gross loans	$	121,030		$	133,496
	Allowance for Loan Losses
	The Company’s Credit Management Division is responsible for regularly reviewing the ALLL methodology for PCI loans. The ALLL for PCI loans is determined separately from total loans, and is based on expectations of future cash flows from the underlying pools of loans or individual loans in accordance with ASC 310-30, as more fully described in Note 3— Summary of Significant Accounting Policies, included in our Annual Report on Form 10-K for the year ended December 31, 2014. As of March 31, 2015 and December 31, 2014, there were no allowance for loan losses recorded for PCI loans.

Loans_and_Lease_Finance_Receiv

Loans and Lease Finance Receivables and Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2015
Receivables [Abstract]
Loans and Lease Finance Receivables and Allowance for Loan Losses	6. LOANS AND LEASE FINANCE RECEIVABLES AND ALLOWANCE FOR LOAN LOSSES
	The following table provides a summary of the total of loan and lease finance receivables, excluding PCI loans, by type.
			March 31, 2015			December 31, 2014
			(Dollars in thousands)
	Commercial and industrial		$	403,600		$	390,011
	SBA			126,385			134,265
	Real estate:
	Commercial real estate			2,499,183			2,487,803
	Construction			55,346			55,173
	SFR mortgage			205,132			205,124
	Dairy & livestock and agribusiness			173,441			279,173
	Municipal lease finance receivables			76,220			77,834
	Consumer and other loans			70,749			69,884
	Gross loans, excluding PCI loans			3,610,056			3,699,267
	Less: Deferred loan fees, net			(8,451	)		(8,567	)
	Gross loans, excluding PCI loans, net of deferred loan fees			3,601,605			3,690,700
	Less: Allowance for loan losses			(60,709	)		(59,825	)
	Net loans, excluding PCI loans			3,540,896			3,630,875
	PCI Loans			121,030			133,496
	Discount on PCI loans			(6,612	)		(7,129	)
	PCI loans, net			114,418			126,367
	Total loans and lease finance receivables		$	3,655,314		$	3,757,242
	As of March 31, 2015, 69.23% of the total gross loan portfolio (excluding PCI loans) consisted of commercial real estate loans and 1.53% of the total loan portfolio consisted of construction loans. Substantially all of the Company’s real estate loans and construction loans are secured by real properties located in California. As of March 31, 2015, $150.9 million, or 6.04%, of the total commercial real estate loans included loans secured by farmland, compared to $165.6 million, or 6.66%, at December 31, 2014. The loans secured by farmland included $131.5 million for loans secured by dairy & livestock land and $19.4 million for loans secured by agricultural land at March 31, 2015, compared to $144.1 million for loans secured by dairy & livestock land and $21.5 million for loans secured by agricultural land at December 31, 2014. As of March 31, 2015, $173.4 million, or 4.80%, of the total gross loan portfolio (excluding PCI loans) consisted of dairy & livestock and agribusiness commercial loans, compared to $279.2 million, or 7.55%, at December 31, 2014. This was comprised of $161.5 million for dairy & livestock loans and $12.0 million for agribusiness loans at March 31, 2015, compared to $268.1 million for dairy & livestock loans and $11.1 million for agribusiness loans at December 31, 2014. At March 31, 2015, the Company held approximately $1.81 billion of total fixed rate loans.
	At March 31, 2015 and December 31, 2014, loans totaling $2.82 billion and $2.78 billion, respectively, were pledged to secure borrowings and available lines of credit from the FHLB and the Federal Reserve Bank.
	Loans Held-for-Sale
	The following table provides a summary of the activity related to loans held-for-sale for the periods presented.
			For the
			Three Months Ended
			March 31,
			2015			2014
			(Dollars in thousands)
	Balance, beginning of period		$	—		$	3,667
	Originations of mortgage loans			—			—
	Sales of mortgage loans			—			—
	Transfer of mortgage loans to held-for-investment			—			—
	Sales of other loans			—			(3,667	)
	Transfers of other loans to held-for-sale			—			—
	Write-down of loans held-for-sale			—			—
	Balance, end of period		$	—		$	—
	Credit Quality Indicators
	Central to our credit risk management is our loan risk rating system. The originating credit officer assigns borrowers an initial risk rating, which is reviewed and confirmed or changed, as appropriate, by Credit Management. Approvals are made based upon the amount of inherent credit risk specific to the transaction and are reviewed for appropriateness by senior line and credit management personnel. Credits are monitored by line and credit management personnel for deterioration in a borrower’s financial condition, which would impact the ability of the borrower to perform under the contract. Risk ratings are adjusted as necessary.
	Loans are risk rated into the following categories (Credit Quality Indicators): Pass, Pass Watch List, Special Mention, Substandard, Doubtful and Loss. Each of these groups is assessed for the proper amount to be used in determining the adequacy of our allowance for losses. These categories can be described as follows:
	Pass – These loans range from minimal credit risk to lower than average, but still acceptable, credit risk.
	Pass Watch List — Pass Watch list loans usually require more than normal management attention. Loans which qualify for the Pass Watch List may involve borrowers with adverse financial trends, higher debt/equity ratios, or weaker liquidity positions, but not to the degree of being considered a defined weakness or problem loan where risk of loss may be apparent.
	Special Mention — Loans assigned to this category are currently protected but are weak. Although concerns exist, the Company is currently protected and loss is unlikely. Such loans have potential weaknesses that may, if not checked or corrected, weaken the asset or inadequately protect the Company’s credit position at some future date.
	Substandard – Loans classified as substandard include poor liquidity, high leverage, and erratic earnings or losses. The primary source of repayment is no longer realistic, and asset or collateral liquidation may be the only source of repayment. Substandard loans are marginal and require continuing and close supervision by credit management. Substandard loans have the distinct possibility that the Company will sustain some loss if deficiencies are not corrected.
	Doubtful – Loans classified doubtful have all the weaknesses inherent in those classified substandard with the added provision that the weaknesses make collection or the liquidation, on the basis of currently existing facts, conditions and values, highly questionable and improbable. The possibility of loss is extremely high, but because of certain important and reasonable specific pending factors which may work to the advantage and strengthening of the assets, their classifications as losses are deferred until their more exact status may be determined.
	Loss — Loans classified as loss are considered uncollectible and of such little value that their continuance as active assets of the Company is not warranted. This classification does not mean that the loan has absolutely no recovery or salvage value, but rather that it is not practical or desirable to defer writing off this basically worthless asset even though partial recovery may be achieved in the future.
	The following tables summarize each class of loans, excluding PCI Loans, according to our internal risk ratings for the periods presented.
			March 31, 2015
			Pass			Watch List			Special Mention		Substandard			Doubtful & Loss		Total
			(Dollars in thousands)
	Commercial and industrial		$	252,537		$	96,106		$	42,377	$	12,350		$	230	$	403,600
	SBA			80,047			22,423			14,362		8,070			1,483		126,385
	Real estate:
	Commercial real estate
	Owner occupied			551,211			139,446			49,994		17,159			—		757,810
	Non-owner occupied			1,390,414			258,838			37,420		54,701			—		1,741,373
	Construction
	Speculative			27,394			3,101			—		7,651			—		38,146
	Non-speculative			16,579			621			—		—			—		17,200
	SFR mortgage			176,298			18,882			4,285		5,667			—		205,132
	Dairy & livestock and agribusiness			103,616			67,149			2,277		296			103		173,441
	Municipal lease finance receivables			38,562			32,403			5,255		—			—		76,220
Consumer and other loans			54,900			10,487			2,670		2,595			97		70,749
Total gross loans, excluding PCI loans		$	2,691,558		$	649,456		$	158,640	$	108,489		$	1,913	$	3,610,056
		December 31, 2014
		Pass			Watch List			Special Mention		Substandard			Doubtful & Loss		Total
		(Dollars in thousands)
Commercial and industrial		$	234,029		$	105,904		$	33,795	$	16,031		$	252	$	390,011
SBA			84,769			24,124			15,858		7,920			1,594		134,265
Real estate:
Commercial real estate
Owner occupied			552,072			159,908			46,248		32,139			—		790,367
Non-owner occupied			1,347,006			241,809			56,353		52,268			—		1,697,436
Construction
Speculative			28,310			613			—		7,651			—		36,574
Non-speculative			18,071			528			—		—			—		18,599
SFR mortgage			174,311			20,218			2,442		8,153			—		205,124
Dairy & livestock and agribusiness			174,783			85,660			8,612		10,015			103		279,173
Municipal lease finance receivables			35,463			22,349			20,022		—			—		77,834
Consumer and other loans			62,904			2,233			1,789		2,763			195		69,884
Total gross loans, excluding PCI loans		$	2,711,718		$	663,346		$	185,119	$	136,940		$	2,144	$	3,699,267
Allowance for Loan Losses
The Company’s Credit Management Division is responsible for regularly reviewing the allowance for loan losses (“ALLL”) methodology, including loss factors and economic risk factors. The Bank’s Director Loan Committee provides Board oversight of the ALLL process and approves the ALLL methodology on a quarterly basis.
Our methodology for assessing the appropriateness of the allowance is conducted on a regular basis and considers the Bank’s overall loan portfolio. Refer to Note 3 – Summary of Significant Accounting Policies of the 2014 Annual Report on Form 10-K for a more detailed discussion concerning the allowance for loan losses.
Management believes that the ALLL was appropriate at March 31, 2015 and December 31, 2014. No assurance can be given that economic conditions which adversely affect the Company’s service areas or other circumstances will not be reflected in increased provisions for loan losses in the future.
The following tables present the balance and activity related to the allowance for loan losses for held-for-investment loans, excluding PCI loans, by portfolio segment for the periods presented.
		For the Three Months Ended March 31, 2015
		Ending			Charge-offs			Recoveries		Provision for			Ending
		Balance								Loan Losses			Balance
		December 31,											March 31,
		2014											2015
		(Dollars in thousands)
Commercial and industrial		$	7,074		$	(134	)	$	35	$	527		$	7,502
SBA			2,557			(33	)		34		(362	)		2,196
Real estate:
Commercial real estate			33,373			—			857		618			34,848
Construction			988			—			9		46			1,043
SFR mortgage			2,344			—			185		(104	)		2,425
Dairy & livestock and agribusiness			5,479			—			99		(1,832	)		3,746
Municipal lease finance receivables			1,412			—			—		(382	)		1,030
Consumer and other loans			1,262			(177	)		9		(269	)		825
Unallocated			5,336			—			—		1,758			7,094
Total allowance for loan losses		$	59,825		$	(344	)	$	1,228	$	—		$	60,709
		For the Three Months Ended March 31, 2014
		Ending			Charge-offs			Recoveries		(Recapture of)			Ending
		Balance								Provision for			Balance
		December 31,								Loan Losses			March 31,
		2013											2014
		(Dollars in thousands)
Commercial and industrial		$	8,502		$	(454	)	$	392	$	(2,072	)	$	6,368
SBA			2,332			—			63		73			2,468
Real estate:
Commercial real estate			39,402			—			68		(70	)		39,400
Construction			1,305			—			778		(1,625	)		458
SFR mortgage			2,718			—			—		(436	)		2,282
Dairy & livestock and agribusiness			11,728			—			144		(2,605	)		9,267
Municipal lease finance receivables			2,335			—			—		(816	)		1,519
Consumer and other loans			960			(13	)		12		(9	)		950
Unallocated			5,953			—			—		60			6,013
Total allowance for loan losses		$	75,235		$	(467	)	$	1,457	$	(7,500	)	$	68,725
The following tables present the recorded investment in loans held-for-investment, excluding PCI loans, and the related allowance for loan losses by portfolio segment, based on the Company’s methodology for determining the allowance for loan losses for the periods presented.
		March 31, 2015
		Recorded Investment in Loans						Allowance for Loan Losses
		Individually			Collectively			Individually		Collectively
		Evaluated for			Evaluated for			Evaluated for		Evaluated for
		Impairment			Impairment			Impairment		Impairment
		(Dollars in thousands)
Commercial and industrial		$	1,611		$	401,989		$	592	$	6,910
SBA			3,158			123,227			42		2,154
Real estate:
Commercial real estate			41,886			2,457,297			154		34,694
Construction			7,651			47,695			—		1,043
SFR mortgage			5,913			199,219			—		2,425
Dairy & livestock and agribusiness			7,277			166,164			—		3,746
Municipal lease finance receivables			—			76,220			—		1,030
Consumer and other loans			881			69,868			6		819
Unallocated			—			—			—		7,094
Total		$	68,377		$	3,541,679		$	794	$	59,915
		March 31, 2014
		Recorded Investment in Loans						Allowance for Loan Losses
		Individually			Collectively			Individually		Collectively
		Evaluated for			Evaluated for			Evaluated for		Evaluated for
		Impairment			Impairment			Impairment		Impairment
		(Dollars in thousands)
Commercial and industrial		$	4,291		$	354,714		$	814	$	5,554
SBA			1,649			129,999			68		2,400
Real estate:
Commercial real estate			33,907			2,160,144			320		39,080
Construction			26,688			16,218			—		458
SFR mortgage			11,692			178,207			47		2,235
Dairy & livestock and agribusiness			27,972			184,985			2,656		6,611
Municipal lease finance receivables			—			81,041			—		1,519
Consumer and other loans			397			54,418			96		854
Unallocated			—			—			—		6,013
Total		$	106,596		$	3,159,726		$	4,001	$	64,724
Past Due and Nonperforming Loans
We seek to manage asset quality and control credit risk through diversification of the loan portfolio and the application of policies designed to promote sound underwriting and loan monitoring practices. The Bank’s Credit Management Division is in charge of monitoring asset quality, establishing credit policies and procedures and enforcing the consistent application of these policies and procedures across the Bank. Reviews of nonperforming, past due loans and larger credits, designed to identify potential charges to the allowance for loan losses, and to determine the appropriateness of the allowance, are conducted on an ongoing basis. These reviews consider such factors as the financial strength of borrowers and any guarantors, the value of the applicable collateral, loan loss experience, estimated loan losses, growth in the loan portfolio, prevailing economic conditions and other factors. Refer to Note 3 – Summary of Significant Accounting Policies, included in our Annual Report on Form 10-K for the year ended December 31, 2014 for additional discussion concerning the Bank’s policy for past due and nonperforming loans.
Loans are reported as a troubled debt restructuring when the Bank grants a concession(s) to a borrower experiencing financial difficulties that the Bank would not otherwise consider. Examples of such concessions include a reduction in the interest rate, deferral of principal or accrued interest, extending the payment due dates or loan maturity date(s), or providing a lower interest rate than would be normally available for new debt of similar risk. As a result of these concessions, restructured loans are classified as impaired. Impairment reserves on non-collateral dependent restructured loans are measured by comparing the present value of expected future cash flows on the restructured loans discounted at the interest rate of the original loan agreement to the loan’s carrying value. These impairment reserves are recognized as a specific component to be provided for in the allowance for loan losses.
Generally, when loans are identified as impaired they are moved to our Special Assets Department. When we identify a loan as impaired, we measure the loan for potential impairment using discounted cash flows, unless the loan is determined to be collateral dependent. In these cases, we use the current fair value of collateral, less selling costs. Generally, the determination of fair value is established through obtaining external appraisals of the collateral.
Speculative construction loans are generally for properties where there is no identified buyer or renter.
The following tables present the recorded investment in the aging of past due and nonaccrual loans, excluding PCI loans, by type of loans for the periods presented.
		March 31, 2015
		30-59			60-89			Total Past		Nonaccrual			Current		Total Loans and
		Days Past			Days Past			Due and		-1					Financing
		Due			Due			Accruing							Receivables
		(Dollars in thousands)
Commercial and industrial		$	112		$	—		$	112	$	952		$	402,536		403,600
SBA			—			—			—		2,463			123,922		126,385
Real estate:
Commercial real estate
Owner occupied			35			—			35		2,418			755,357		757,810
Non-owner occupied			—			—			—		14,369			1,727,004		1,741,373
Construction
Speculative			—			—			—		—			38,146		38,146
Non-speculative			—			—			—		—			17,200		17,200
SFR mortgage			1,613			—			1,613		2,233			201,286		205,132
Dairy & livestock and agribusiness			—			—			—		103			173,338		173,441
Municipal lease finance receivables			—			—			—		—			76,220		76,220
Consumer and other loans			119			20			139		463			70,147		70,749
Total gross loans, excluding PCI Loans		$	1,879		$	20		$	1,899	$	23,001		$	3,585,156	$	3,610,056
-1	As of March 31, 2015, $20.3 million of nonaccruing loans were current, $553,000 were 30-59 days past due, $86,000 were 60-89 days past due and $2.0 million were 90+ days past due.
		December 31, 2014
		30-59			60-89			Total Past		Nonaccrual			Current		Total Loans and
		Days Past			Days Past			Due and		-1					Financing
		Due			Due			Accruing							Receivables
		(Dollars in thousands)
Commercial and industrial		$	943		$	35		$	978	$	2,308		$	386,725	$	390,011
SBA			75			—			75		2,481			131,709		134,265
Real estate:
Commercial real estate
Owner occupied			36			86			122		4,072			786,173		790,367
Non-owner occupied			—			—			—		19,246			1,678,190		1,697,436
Construction
Speculative			—			—			—		—			36,574		36,574
Non-speculative			—			—			—		—			18,599		18,599
SFR mortgage			425			—			425		3,240			201,459		205,124
Dairy & livestock and agribusiness			—			—			—		103			279,070		279,173
Municipal lease finance receivables			—			—			—		—			77,834		77,834
Consumer and other loans			64			17			81		736			69,067		69,884
Total gross loans, excluding PCI Loans		$	1,543		$	138		$	1,681	$	32,186		$	3,665,400	$	3,699,267
-1	As of December 31, 2014, $20.1 million of nonaccruing loans were current, $3.7 million were 30-59 days past due, $8.5 million were 90+ days.
Impaired Loans
At March 31, 2015, the Company had impaired loans, excluding PCI loans, of $68.4 million. Of this amount, there were $16.8 million of nonaccrual commercial real estate loans, $2.2 million of nonaccrual SFR mortgage loans, $952,000 of nonaccrual commercial and industrial loans, $103,000 of nonaccrual dairy & livestock and agribusiness loans and $463,000 of nonaccrual consumer and other loans. These impaired loans included $62.2 million of loans whose terms were modified in a troubled debt restructuring, of which $16.8 million were classified as nonaccrual. The remaining balance of $45.4 million consisted of 34 loans performing according to the restructured terms. The impaired loans had a specific allowance of $794,000 at March 31, 2015. At December 31, 2014, the Company had classified as impaired loans, excluding PCI loans, with a balance of $85.8 million with a related allowance of $1.5 million.
The following tables present information for held-for-investment loans, excluding PCI loans, individually evaluated for impairment by class of loans, as of and for the periods indicated below.
		As of and For the Three Months Ended
		31-Mar-15
		Recorded			Unpaid			Related		Average			Interest
		Investment			Principal			Allowance		Recorded			Income
					Balance					Investment			Recognized
		(Dollars in thousands)
With no related allowance recorded:
Commercial and industrial		$	1,004		$	1,819		$	—	$	1,017		$	8
SBA			3,117			3,667			—		3,177			13
Real estate:
Commercial real estate
Owner occupied			6,117			7,167			—		6,185			64
Non-owner occupied			34,808			42,718			—		35,194			350
Construction
Speculative			7,651			7,651			—		7,651			96
Non-speculative			—			—			—		—			—
SFR mortgage			5,913			6,642			—		5,940			27
Dairy & livestock and agribusiness			7,277			8,991			—		7,533			85
Municipal lease finance receivables			—			—			—		—			—
Consumer and other loans			783			1,289			—		836			4
Total			66,670			79,944			—		67,533			647
With a related allowance recorded:
Commercial and industrial			607			680			592		617			—
SBA			41			54			42		45			—
Real estate:
Commercial real estate
Owner occupied			—			—			—		—			—
Non-owner occupied			961			1,278			154		973			—
Construction
Speculative			—			—			—		—			—
Non-speculative			—			—			—		—			—
SFR mortgage			—			—			—		—			—
Dairy & livestock and agribusiness			—			—			—		—			—
Municipal lease finance receivables			—			—			—		—			—
Consumer and other loans			98			107			6		99			—
Total			1,707			2,119			794		1,734			—
Total impaired loans		$	68,377		$	82,063		$	794	$	69,267		$	647
		As of and For the Three Months Ended
		31-Mar-14
		Recorded			Unpaid			Related		Average			Interest
		Investment			Principal			Allowance		Recorded			Income
					Balance					Investment			Recognized
		(Dollars in thousands)
With no related allowance recorded:
Commercial and industrial		$	2,592		$	2,862		$	—	$	2,596		$	15
SBA			1,581			1,997			—		1,634			—
Real estate:
Commercial real estate
Owner occupied			10,108			10,768			—		10,221			117
Non-owner occupied			21,928			27,740			—		22,103			215
Construction
Speculative			17,519			18,407			—		17,550			77
Non-speculative			9,169			9,169			—		9,184			140
SFR mortgage			11,214			12,911			—		11,266			26
Dairy & livestock and agribusiness			16,582			17,430			—		16,902			189
Municipal lease finance receivables			—			—			—		—			—
Consumer and other loans			290			295			—		291			—
Total			90,983			101,579			—		91,747			779
With a related allowance recorded:
Commercial and industrial			1,699			2,033			814		1,701			—
SBA			68			76			68		70			—
Real estate:
Commercial real estate
Owner occupied			1,871			2,344			320		1,871			—
Non-owner occupied			—			—			—		—			—
Construction
Speculative			—			—			—		—			—
Non-speculative			—			—			—		—			—
SFR mortgage			478			486			47		479			—
Dairy & livestock and agribusiness			11,390			12,042			2,656		11,608			75
Municipal lease finance receivables			—			—			—		—			—
Consumer and other loans			107			165			96		107			—
Total			15,613			17,146			4,001		15,836			75
Total impaired loans		$	106,596		$	118,725		$	4,001	$	107,583		$	854
		As of December 31, 2014
		Recorded			Unpaid			Related
		Investment			Principal			Allowance
					Balance
		(Dollars in thousands)
With no related allowance recorded:
Commercial and industrial		$	2,391		$	3,624		$	—
SBA			1,853			2,197			—
Real estate:
Commercial real estate
Owner occupied			16,961			18,166			—
Non-owner occupied			30,068			38,156			—
Construction
Speculative			7,651			7,651			—
Non-speculative			—			—			—
SFR mortgage			6,512			7,493			—
Dairy & livestock and agribusiness			15,796			17,587			—
Municipal lease finance receivables			—			—			—
Consumer and other loans			673			1,094			—
Total			81,905			95,968			—
With a related allowance recorded:
Commercial and industrial			629			698			615
SBA			1,327			1,591			296
Real estate:
Commercial real estate
Owner occupied			—			—			—
Non-owner occupied			982			1,278			154
Construction
Speculative			—			—			—
Non-speculative			—			—			—
SFR mortgage			467			484			35
Dairy & livestock and agribusiness			—			—			—
Municipal lease finance receivables			—			—			—
Consumer and other loans			482			508			449
Total			3,887			4,559			1,549
Total impaired loans		$	85,792		$	100,527		$	1,549
The Company recognizes the charge-off of impairment allowance on impaired loans in the period in which a loss is identified for collateral dependent loans. Therefore, the majority of the nonaccrual loans as of March 31, 2015 and December 31, 2014 have already been written down to the estimated net realizable value. The impaired loans with a related allowance recorded are on nonaccrual loans where a charge-off is not yet processed, on nonaccrual SFR loans where there is a potential modification in process, or on smaller balance non-collateral dependent loans.
Reserve for Unfunded Loan Commitments
The allowance for off-balance sheet credit exposure relates to commitments to extend credit, letters of credit and undisbursed funds on lines of credit. The Company evaluates credit risk associated with the off-balance sheet commitments at the same time it evaluates credit risk associated with the loan and lease portfolio. The Company recorded a reduction of the reserve for unfunded loan commitments of $500,000 for the quarter ended March 31, 2015, compared with no provision or reduction of the reserve for unfunded loan commitments for the same period of 2014. At March 31, 2015 and December 31, 2014, the balance of the reserve was $7.2 million and $7.7 million, respectively, and was included in other liabilities.
Troubled Debt Restructurings (“TDRs”)
Loans that are reported as TDRs are considered impaired and charge-off amounts are taken on an individual loan basis, as deemed appropriate. The majority of restructured loans are loans for which the terms of repayment have been renegotiated, resulting in a reduction in interest rate or deferral of principal. Refer to Note 3 – Summary of Significant Accounting Policies, included in our Annual Report on Form 10-K for the year ended December 31, 2014 for a more detailed discussion regarding TDRs.
As of March 31, 2015, there were $62.2 million of loans classified as TDRs, of which $16.8 million were nonperforming and $45.4 million were performing. TDRs on accrual status are comprised of loans that were accruing interest at the time of restructuring or have demonstrated repayment performance in compliance with the restructured terms for a sustained period and for which the Company anticipates full repayment of both principal and interest. At March 31, 2015, performing TDRs were comprised of 12 commercial real estate loans of $25.1 million, one construction loan of $7.6 million, five dairy & livestock loans of $7.2 million, 11 SFR mortgage loans of $3.7 million, four commercial and industrial loans of $1.4 million and one consumer other loan of $418,000. There were no loans removed from TDR classification during the quarters ended March 31, 2015 and 2014.
The majority of TDRs have no specific allowance allocated as any impairment amount is normally charged off at the time a probable loss is determined. We have allocated $707,000 and $726,000 of specific allowance to TDRs as of March 31, 2015 and December 31, 2014, respectively.
The following tables provide a summary of the activity related to TDRs for the periods presented.
		For the Three Months March 31,
		2015			2014
		(Dollars in thousands)
Performing TDRs:
Beginning balance		$	53,589		$	66,955
New modifications			—			41
Payoffs and payments, net			(8,729	)		(602	)
TDRs returned to accrual status			516			—
TDRs placed on nonaccrual status			—			—
Ending balance		$	45,376		$	66,394
		For the Three Months March 31,
		2015			2014
		(Dollars in thousands)
Nonperforming TDRs:
Beginning balance		$	20,285		$	25,119
New modifications (1)			—			—
Charge-offs			—			—
Payoffs and payments, net			(2,995	)		(1,151	)
TDRs returned to accrual status			(516	)		—
TDRs placed on nonaccrual status			—			—
Ending balance		$	16,774		$	23,968
The following tables summarize loans modified as troubled debt restructurings for the periods presented.
Modifications (1)
		For the Three Months Ended March 31, 2015
		Number of			Pre-Modification			Post-Modification		Outstanding Recorded			Financial Effect
		Loans			Outstanding			Outstanding		Investment at			Resulting From
					Recorded			Recorded		March 31, 2015			Modifications (2)
					Investment			Investment
		(Dollars in thousands)
Commercial and industrial:
Interest rate reduction			—		$	—		$	—	$	—		$	—
Change in amortization period or maturity			—			—			—		—			—
Real estate:
Commercial real estate:
Owner occupied
Interest rate reduction			—			—			—		—			—
Change in amortization period or maturity			—			—			—		—
Non-owner occupied
Interest rate reduction			—			—			—		—			—
Change in amortization period or maturity			—			—			—		—			—
Dairy & livestock and agribusiness:
Interest rate reduction			—			—			—		—			—
Change in amortization period or maturity			—			—			—		—			—
Consumer
Interest rate reduction			—			—			—		—			—
Total loans			—		$	—		$	—	$	—		$	—
		For the Three Months Ended March 31, 2014
		Number of			Pre-Modification			Post-Modification		Outstanding Recorded			Financial Effect
		Loans			Outstanding			Outstanding		Investment at			Resulting From
					Recorded			Recorded		March 31, 2014			Modifications (2)
					Investment			Investment
		(Dollars in thousands)
Commercial and industrial:
Interest rate reduction			—		$	—		$	—	$	—		$	—
Change in amortization period or maturity			1			41			41		39			—
Real estate:
Commercial real estate:
Owner occupied
Interest rate reduction			—			—			—		—			—
Change in amortization period or maturity			—			—			—		—			—
Non-owner occupied						—
Interest rate reduction			—			—			—		—
Change in amortization period or maturity			—			—			—		—			—
Dairy & livestock and agribusiness:
Interest rate reduction			—			—			—		—			—
Change in amortization period or maturity						—
Consumer
Interest rate reduction			—			—			—		—			—
Total loans			1		$	41		$	41	$	39		$	—
-1	The tables exclude modified loans that were paid off prior to the end of the period.
-2	Financial effects resulting from modifications represent charge-offs and specific allowance recorded at modification date.
As of March 31, 2015, there were no loans that were previously modified as a TDRs within the previous 12 months that subsequently defaulted during the three months ended March 31, 2015.

Earnings_Per_Share_Reconciliat

Earnings Per Share Reconciliation	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share Reconciliation	7. EARNINGS PER SHARE RECONCILIATION
	Basic earnings per common share are computed by dividing income allocated to common stockholders by the weighted-average number of common shares outstanding during each period. The computation of diluted earnings per common share considers the number of tax-effected shares issuable upon the assumed exercise of outstanding common stock options. Antidilutive common shares are not included in the calculation of diluted earnings per common share. For the three months ended March 31, 2015 and 2014, shares deemed to be antidilutive, and thus excluded from the computation of earnings per common share were 235,000 and 130,000 shares, respectively.
	The table below summarizes earnings per common share and diluted earnings per common share, and reconciles the numerator and denominator of both earnings per common share calculations.
		For the Thee Months Ended March 31,
		2015		2014
		(In thousands, except per share amounts)
	Earnings per common share:
	Net earnings	$	15,833	$	28,661
	Less: Net earnings allocated to restricted stock		81		127
	Net earnings allocated to common shareholders	$	15,752	$	28,534
	Weighted average shares outstanding		105,523		105,192
	Basic earnings per common share	$	0.15	$	0.27
	Diluted earnings per common share:
	Net income allocated to common shareholders	$	15,752	$	28,534
	Weighted average shares outstanding		105,523		105,192
	Incremental shares from assumed exercise of outstanding options		436		599
	Diluted weighted average shares outstanding		105,959		105,791
	Diluted earnings per common share	$	0.15	$	0.27

Fair_Value_Information

Fair Value Information	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Information	8. FAIR VALUE INFORMATION
	Fair Value Hierarchy
	Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date.
	The following disclosure provides the fair value information for financial assets and liabilities as of March 31, 2015. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels (Level 1, Level 2, and Level 3).
		•		Level 1 — Valuation is based upon quoted prices for identical instruments traded in active markets.
		•		Level 2 — Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market.
		•		Level 3 — Valuation is generated from model-based techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect the Company’s own estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of option pricing models, discounted cash flows and similar techniques.
	There were no transfers in and out of Level 1 and Level 2 measurements during the three months ended March 31, 2015 and 2014.
	Determination of Fair Value
	The following is a description of valuation methodologies used for assets and liabilities recorded at fair value and for estimating fair value for financial instruments not recorded at fair value.
	Cash and Cash Equivalents— The carrying amount of cash and cash equivalents is considered to approximate fair value due to the liquidity of these instruments.
	Interest-Bearing Balances Due from Depository Institutions — The carrying value of due from depository institutions is considered to approximate fair value due to the short-term nature of these deposits.
	FHLB Stock — The carrying amount of FHLB stock approximates fair value, as the stock may be sold back to the FHLB at carrying value.
	Investment Securities Held–to- Maturity — Investment securities held-to-maturity are valued based upon quotes obtained from an independent third-party pricing service. The Company categorized its held-to-maturity investment as a Level 3 valuation.
	Investment Securities Available-for-Sale — Investment securities available-for-sale are generally valued based upon quotes obtained from an independent third-party pricing service, which uses evaluated pricing applications and model processes. Observable market inputs, such as, benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data are considered as part of the evaluation. The inputs are related directly to the security being evaluated, or indirectly to a similarly situated security. Market assumptions and market data are utilized in the valuation models. The Company reviews the market prices provided by the third-party pricing service for reasonableness based on the Company’s understanding of the market place and credit issues related to the securities. The Company has not made any adjustments to the market quotes provided by them and accordingly, the Company categorized its investment portfolio within Level 2 of the fair value hierarchy.
	Loans Held-for-Sale — Loans held-for-sale are carried at the lower of cost or fair value. The fair value is derived from third party sale analysis, existing sale agreements, or appraisal reports on the loans’ underlying collateral.
	Loans — The carrying amount of loans and lease finance receivables is their contractual amounts outstanding, reduced by deferred net loan origination fees, purchase price discounts and the allocable portion of the allowance for loan losses.
	The fair value of loans, other than loans on nonaccrual status, was estimated by discounting the remaining contractual cash flows using the estimated current rate at which similar loans would be made to borrowers with similar credit risk characteristics and for the same remaining maturities, reduced by deferred net loan origination fees and the allocable portion of the allowance for loan losses. Accordingly, in determining the estimated current rate for discounting purposes, no adjustment has been made for any change in borrowers’ specific credit risks since the origination or purchase of such loans. Rather, the allocable portion of the allowance for loan losses and the purchase price discounts are considered to provide for such changes in estimating fair value. As a result, this fair value is not necessarily the value which would be derived using an exit price. These loans are included within Level 3 of the fair value hierarchy.
	Impaired loans and OREO are generally measured using the fair value of the underlying collateral, which is determined based on the most recent appraisal information received, less costs to sell. Appraised values may be adjusted based on factors such as the changes in market conditions from the time of valuation or discounted cash flows of the property. As such, these loans and OREO fall within Level 3 of the fair value hierarchy.
	The majority of our commitments to extend credit carry current market interest rates if converted to loans. Because these commitments are generally unassignable by either the borrower or us, they only have value to the borrower and us. The estimated fair value approximates the recorded deferred fee amounts and is excluded from the following table because it is not material.
	Swaps — The fair value of the interest rate swap contracts are provided by our counterparty using a system that constructs a yield curve based on cash LIBOR rates, Eurodollar futures contracts, and 3-year through 30-year swap rates. The yield curve determines the valuations of the interest rate swaps. Accordingly, the swap is categorized as a Level 2 valuation.
	Deposits & Borrowings — The amounts payable to depositors for demand, savings, and money market accounts, and short-term borrowings are considered to approximate fair value. The fair value of fixed-maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. The fair value of long-term borrowings and junior subordinated debentures is estimated using the rates currently offered for borrowings of similar remaining maturities. Interest-bearing deposits and borrowings are included within Level 2 of the fair value hierarchy.
	Accrued Interest Receivable/Payable — The amounts of accrued interest receivable on loans and lease finance receivables and investments and accrued interest payable on deposits and borrowings are considered to approximate fair value and are included within Level 2 of the fair value hierarchy.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	The tables below present the balances of assets and liabilities measured at fair value on a recurring basis for the periods presented.
			Carrying Value at		Quoted Prices in		Significant Other		Significant
					Active Markets		Observable Inputs		Unobservable
					for Identical				Inputs
					Assets
			March 31, 2015		(Level 1)		(Level 2)		(Level 3)
			(Dollars in thousands)
	Description of assets
	Investment securities - AFS:
	Government agency		$	329,866	$	—	$	329,866	$	—
	Residential mortgage-backed securities			1,855,154		—		1,855,154		—
	CMO’s / REMIC’s - residential			288,244		—		288,244		—
	Municipal bonds			549,844		—		549,844		—
	Other securities			5,181		—		5,181		—
	Total investment securities - AFS			3,028,289		—		3,028,289		—
	Interest rate swaps			11,624		—		11,624		—
	Total assets		$	3,039,913	$	—	$	3,039,913	$	—
	Description of liability
	Interest rate swaps		$	11,624	$	—	$	11,624	$	—
	Total liabilities		$	11,624	$	—	$	11,624	$	—
			Carrying Value at		Quoted Prices in		Significant Other		Significant
					Active Markets		Observable Inputs		Unobservable
					for Identical				Inputs
					Assets
			December 31, 2014		(Level 1)		(Level 2)		(Level 3)
			(Dollars in thousands)
	Description of assets
	Investment securities - AFS:
	Government agency		$	330,843	$	—	$	330,843	$	—
	Residential mortgage-backed securities			1,917,496		—		1,917,496		—
	CMO’s / REMIC’s - residential			304,091		—		304,091		—
	Municipal bonds			579,641		—		579,641		—
	Other securities			5,087		—		5,087		—
	Total investment securities - AFS			3,137,158		—		3,137,158		—
	Interest rate swaps			10,080		—		10,080		—
	Total assets		$	3,147,238	$	—	$	3,147,238	$	—
	Description of liability
	Interest rate swaps		$	10,080	$	—	$	10,080	$	—
	Total liabilities		$	10,080	$	—	$	10,080	$	—
	Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis
We may be required to measure certain assets at fair value on a non-recurring basis in accordance with GAAP. These adjustments to fair value usually result from application of lower of cost or fair value accounting or write-downs of individual assets. For assets measured at fair value on a non-recurring basis that were still held on the balance sheet at March 31, 2015 and December 31, 2014, respectively, the following tables provide the level of valuation assumptions used to determine each adjustment and the carrying value of the related assets for investments that experienced losses during the period.
		Carrying Value at		Quoted Prices in		Significant		Significant		Total Losses
				Active Markets		Other		Unobservable		For the Three
				for Identical		Observable		Inputs		Months Ended
				Assets		Inputs
		March 31, 2015		(Level 1)		(Level 2)		(Level 3)		March 31, 2015
		(Dollars in thousands)
Description of assets
Impaired loans, excluding PCI Loans:
Commercial and industrial		$	—	$	—	$	—	$	—	$	—
SBA			—		—		—		—		—
Real estate:
Commercial real estate			—		—		—		—		—
Construction			—		—		—		—		—
SFR mortgage			—		—		—		—		—
Dairy & livestock and agribusiness			—		—		—		—		—
Consumer and other loans			209		—		—		209		76
Other real estate owned			340		—		—		340		33
Total assets		$	549	$	—	$	—	$	549	$	109
		Carrying Value at		Quoted Prices in		Significant		Significant		Total Losses
				Active Markets		Other		Unobservable		For the Year Ended
				for Identical		Observable		Inputs
				Assets		Inputs
		December 31, 2014		(Level 1)		(Level 2)		(Level 3)		31-Dec-14
		(Dollars in thousands)
Description of assets
Impaired loans, excluding PCI Loans:
Commercial and industrial		$	1,911	$	—	$	—	$	1,911	$	771
SBA			1,327		—		—		1,327		296
Real estate:
Commercial real estate			2,500		—		—		2,500		271
Construction			—		—		—		—		—
SFR mortgage			—		—		—		—		—
Dairy & livestock and agribusiness			103		—		—		103		1,061
Consumer and other loans			482		—		—		482		447
Other real estate owned			—		—		—		—		—
Total assets		$	6,323	$	—	$	—	$	6,323	$	2,846
Fair Value of Financial Instruments
The following disclosure presents estimated fair value of financial instruments. The estimated fair value amounts have been determined by the Company using available market information and appropriate valuation methodologies. However, considerable judgment is required to develop the estimates of fair value. Accordingly, the estimates presented below are not necessarily indicative of the amounts the Company may realize in a current market exchange as of March 31, 2015 and December 31, 2014, respectively. The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts.
		March 31, 2015
				Estimated Fair Value
		Carrying		Level 1		Level 2		Level 3		Total
		Amount
		(Dollars in thousands)
Assets
Total cash and cash equivalents		$	401,372	$	401,372	$	—	$	—	$	401,372
Interest-earning balances due from depository institutions			25,873		—		25,873		—		25,873
FHLB stock			25,338		—		25,338		—		25,338
Investment securities available-for-sale			3,028,289		—		3,028,289		—		3,028,289
Investment securities held-to-maturity			1,464		—		—		2,040		2,040
Loans held-for-sale			—		—		—		—		—
Total loans, net of allowance for loan losses			3,655,314		—		—		3,704,042		3,704,042
Accrued interest receivable			22,872		—		22,872		—		22,872
Swaps			11,624		—		11,624		—		11,624
Liabilities
Deposits:
Noninterest-bearing		$	3,126,928	$	3,126,928	$	—	$	—	$	3,126,928
Interest-bearing			2,770,848		—		2,771,030		—		2,771,030
Borrowings			560,352		—		560,291		—		560,291
Junior subordinated debentures			25,774		—		26,016		—		26,016
Accrued interest payable			306		—		306		—		306
Swaps			11,624		—		11,624		—		11,624
		December 31, 2014
				Estimated Fair Value
		Carrying		Level 1		Level 2		Level 3		Total
		Amount
		(Dollars in thousands)
Assets
Total cash and cash equivalents		$	105,768	$	105,768	$	—	$	—	$	105,768
Interest-earning balances due from depository institutions			27,118		—		27,118		—		27,118
FHLB stock			25,338		—		25,338		—		25,338
Investment securities available-for-sale			3,137,158		—		3,137,158		—		3,137,158
Investment securities held-to-maturity			1,528		—		—		2,177		2,177
Loans held-for-sale			—		—		—		—		—
Total loans, net of allowance for loan losses			3,757,242		—		—		3,794,454		3,794,454
Accrued interest receivable			23,194		—		23,194		—		23,194
Swaps			10,080		—		10,080		—		10,080
Liabilities
Deposits:
Noninterest-bearing		$	2,866,365	$	2,866,365	$	—	$	—	$	2,866,365
Interest-bearing			2,738,293		—		2,739,221		—		2,739,221
Borrowings			809,106		—		822,607		—		822,607
Junior subordinated debentures			25,774		—		26,005		—		26,005
Accrued interest payable			1,161		—		1,161		—		1,161
Swaps			10,080		—		10,080		—		10,080
The fair value estimates presented herein are based on pertinent information available to management as of March 31, 2015 and December 31, 2014. Although management is not aware of any factors that would significantly affect the estimated fair value amounts, such amounts have not been comprehensively revalued for purposes of these financial statements since that date, and therefore, current estimates of fair value may differ significantly from the amounts presented above.

Business_Segments

Business Segments	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Business Segments	9. BUSINESS SEGMENTS
	The Company has identified two principal reportable segments: Business Financial and Commercial Banking Centers (“Centers”) and the Treasury Department. The Company’s subsidiary bank has 40 Business Financial Centers and seven Commercial Banking Centers organized in geographic regions, which are the focal points for customer sales and services. The Company utilizes an internal reporting system to measure the performance of various operating segments within the Bank which is the basis for determining the Bank’s reportable segments. The chief operating decision maker (currently our CEO) regularly reviews the financial information of these segments in deciding how to allocate resources and to assess performance. Centers are considered one operating segment as their products and services are similar and are sold to similar types of customers, have similar production and distribution processes, have similar economic characteristics, and have similar reporting and organizational structures. The Treasury Department’s primary focus is managing the Bank’s investments, liquidity and interest rate risk. Information related to the Company’s remaining operating segments, which include construction lending, dairy & livestock and agribusiness lending, leasing, CitizensTrust, and centralized functions have been aggregated and included in “Other.” In addition, the Company allocates internal funds transfer pricing to the segments using a methodology that charges users of funds interest expense and credits providers of funds interest income with the net effect of this allocation being recorded in administration.
	The following table represents the selected financial information for these two business segments. GAAP does not have an authoritative body of knowledge regarding the management accounting used in presenting segment financial information. The accounting policies for each of the business units is the same as those policies identified for the consolidated Company and disclosed in Note 3 — Summary of Significant Accounting Policies, included in our Annual Report on Form 10-K for the year ended December 31, 2014. The income numbers represent the actual income and expenses of each business unit. In addition, each segment has allocated income and expenses based on management’s internal reporting system, which allows management to determine the performance of each of its business units. Loan fees included in the Centers category are the actual loan fees paid to the Company by its customers. These fees are eliminated and deferred in the “Other” category, resulting in deferred loan fees for the condensed consolidated financial statements. All income and expense items not directly associated with the two business segments are grouped in the “Other” category. Future changes in the Company’s management structure or reporting methodologies may result in changes in the measurement of operating segment results.
	The following tables present the operating results and other key financial measures for the individual operating segments for the periods presented.
			For the Three Months Ended March 31, 2015
			Centers		Treasury			Other			Eliminations			Total
			(Dollars in thousands)
	Interest income, including loan fees		$	35,368	$	18,655		$	10,157		$	—		$	64,180
	Credit for funds provided (1)			8,211		—			12,641			(20,852	)		—
	Total interest income			43,579		18,655			22,798			(20,852	)		64,180
	Interest expense			1,663		1,431			77			—			3,171
	Charge for funds used (1)			1,067		14,806			4,979			(20,852	)		—
	Total interest expense			2,730		16,237			5,056			(20,852	)		3,171
	Net interest income			40,849		2,418			17,742			—			61,009
	Provision for loan losses			—		—			—			—			—
	Net interest income after provision for loan losses			40,849		2,418			17,742			—			61,009
	Noninterest income			5,067		—			2,944			—			8,011
	Noninterest expense			11,849		213			18,540			—			30,602
	Debt termination expense			—		13,870			—			—			13,870
	Segment pre-tax profit		$	34,067	$	(11,665	)	$	2,146		$	—		$	24,548
	Segment assets as of March 31, 2015		$	6,216,028	$	3,450,529		$	898,554		$	(3,122,160	)	$	7,442,951
	-1	Credit for funds provided and charges for funds used are eliminated in the condensed consolidated presentation.
			For the Three Months Ended March 31, 2014
			Centers		Treasury			Other			Eliminations			Total
			(Dollars in thousands)
	Interest income, including loan fees		$	33,091	$	16,432		$	11,539		$	—		$	61,062
	Credit for funds provided (1)			7,074		—			11,463			(18,537	)		—
	Total interest income			40,165		16,432			23,002			(18,537	)		61,062
	Interest expense			1,637		2,373			110			—			4,120
	Charge for funds used (1)			1,090		12,797			4,650			(18,537	)		—
	Total interest expense			2,727		15,170			4,760			(18,537	)		4,120
	Net interest income			37,438		1,262			18,242			—			56,942
	Provision for loan losses			—		—			(7,500	)		—			(7,500	)
	Net interest income after provision for loan losses			37,438		1,262			25,742			—			64,442
	Noninterest income			4,782		—			6,716			—			11,498
	Noninterest expense			11,828		196			19,133			—			31,157
	Debt termination expense			—		—			—			—			—
	Segment pre-tax profit		$	30,392	$	1,066		$	13,325		$	—		$	44,783
	Segment assets as of March 31, 2014		$	5,525,494	$	3,264,736		$	843,026		$	(2,730,738	)	$	6,902,518
	-1	Credit for funds provided and charges for funds used are eliminated in the condensed consolidated presentation.

Derivative_Financial_Instrumen

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	10. DERIVATIVE FINANCIAL INSTRUMENTS
	The Bank is exposed to certain risks relating to its ongoing business operations and utilizes interest rate swap agreements (“swaps”) as part of its asset/liability management strategy to help manage its interest rate risk position. As of March 31, 2015, the Bank has entered into 75 interest-rate swap agreements with customers, all of which also involve a counterparty bank. The swap agreements are not designated as hedging instruments. The purpose of entering into offsetting derivatives not designated as a hedging instrument is to provide the Bank a variable-rate loan receivable and provide the customer the financial effects of a fixed-rate loan without creating significant volatility in the Bank’s earnings.
	The structure of the swaps is as follows. The Bank enters into a swap with its customers to allow them to convert variable rate loans to fixed rate loans, and at the same time, the Bank enters into a swap with the counterparty bank to allow the Bank to pass on the interest-rate risk associated with fixed rate loans. The net effect of the transaction allows the Bank to receive interest on the loan from the customer at a variable rate based on LIBOR plus a spread. The changes in the fair value of the swaps primarily offset each other and therefore should not have a significant impact on the Company’s results of operations, although the Company does incur credit and counterparty risk with respect to performance on the swap agreements by the Bank’s customer and counterparty, respectively. Our interest rate swap derivatives are subject to a master netting arrangement with one counterparty bank. None of our derivative assets and liabilities are offset in the balance sheet.
	We believe our risk of loss associated with our counterparty borrowers related to interest rate swaps is mitigated as the loans with swaps are underwritten to take into account potential additional exposure, although there can be no assurances in this regard since the performance of our swaps is subject to market and counterparty risk.
	Balance Sheet Classification of Derivative Financial Instruments
	As of March 31, 2015 and December 31, 2014, the total notional amount of the Company’s swaps was $193.8 million, and $197.4 million, respectively. The location of the asset and liability, and their respective fair values are summarized in the table below.
		March 31, 2015
		Asset Derivatives			Liability Derivatives
		Balance Sheet	Fair		Balance Sheet	Fair
		Location	Value		Location	Value
		(Dollars in thousands)
	Derivatives not designated as hedging instruments:
	Interest rate swaps	Other assets	$	11,624	Other liabilities	$	11,624
	Total derivatives		$	11,624		$	11,624
		31-Dec-14
		Asset Derivatives			Liability Derivatives
		Balance Sheet	Fair		Balance Sheet	Fair
		Location	Value		Location	Value
		(Dollars in thousands)
	Derivatives not designated as hedging instruments:
	Interest rate swaps	Other assets	$	10,080	Other liabilities	$	10,080
	Total derivatives		$	10,080		$	10,080
	The Effect of Derivative Financial Instruments on the Condensed Consolidated Statements of Earnings
	There was no gain recognized in the condensed consolidated statements of earnings for the three months ended March 31, 2015 and 2014.

Other_Comprehensive_Income_Los

Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Other Comprehensive Income (Loss)	11. OTHER COMPREHENSIVE INCOME (LOSS)
	The tables below provide a summary of the components of other comprehensive income (“OCI”) for the periods presented.
		For the Three Months Ended March 31, 2015
		Before-Tax			Tax Effect		After-Tax
		(Dollars in thousands)
	Investment securities available-for-sale:
	Net change in fair value recorded in accumulated OCI	$	20,270		$	8,514	$	11,756
	Net change	$	20,270		$	8,514	$	11,756
		For the Three Months Ended March 31, 2014
		Before-Tax			Tax Effect		After-Tax
		(Dollars in thousands)
	Investment securities available-for-sale:
	Net change in fair value recorded in accumulated OCI	$	24,781		$	10,407	$	14,374
	Net change	$	24,781		$	10,407	$	14,374
	The following table provides a summary of the change in accumulated other comprehensive income for the periods presented.
		Investment Securities
		Available-for-Sale
		(Dollars in thousands)
	Balance, January 1, 2015	$	31,075
	Net change in fair value recorded in accumulated OCI		11,756
	Net realized gains reclassified into earnings		—
	Balance, March 31, 2015	$	42,831
		Investment Securities
		Available-for-Sale
		(Dollars in thousands)
	Balance, January 1, 2014	$	(9,330	)
	Net change in fair value recorded in accumulated OCI		14,374
	Net realized gains reclassified into earnings		—
	Balance, March 31, 2014	$	5,044

Balance_Sheet_Offsetting

Balance Sheet Offsetting	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
Balance Sheet Offsetting	12. BALANCE SHEET OFFSETTING
	Assets and liabilities relating to certain financial instruments, including, derivatives and securities sold under repurchase agreements (“repurchase agreements”), may be eligible for offset in the condensed consolidated balance sheets as permitted under accounting guidance. As noted above, our interest rate swap derivatives are subject to a master netting arrangement with one counterparty bank. Our interest rate swap derivatives require the Company to pledge investment securities as collateral based on certain risk thresholds. Investment securities that have been pledged by the Company to the counterparty bank continue to be reported in the Company’s condensed consolidated balance sheets unless the Company defaults. In November 2006, we began offering a repurchase agreement product to our customers, which include master netting agreements that allow for the netting of collateral positions. This product, known as Citizens Sweep Manager, sells certain of our securities overnight to our customers under an agreement to repurchase them the next day. The repurchase agreements are not offset in the condensed consolidated balances.
		Gross Amounts		Gross Amounts			Net Amounts of		Gross Amounts Not Offset in					Net Amount
		Recognized in		offset in the			Assets Presented		the Condensed Consolidated
		the Condensed		Condensed			in the Condensed		Balance Sheets
		Consolidated		Consolidated			Consolidated
		Balance Sheets		Balance Sheets			Balance Sheets		Financial		Collateral
									Instruments		Pledged
		(Dollars in thousands)
	March 31, 2015
	Financial assets:
	Derivatives not designated as hedging instruments	$	11,624	$	—		$	—	$	11,624	$	—		$	11,624
	Total	$	11,624	$	—		$	—	$	11,624	$	—		$	11,624
	Financial liabilities:
	Derivatives not designated as hedging instruments	$	11,624	$	—		$	11,624	$	—	$	(16,761	)	$	(5,137	)
	Repurchase agreements		560,352		—			560,352		—		(687,017	)		(126,665	)
	Total	$	571,976	$	—		$	571,976	$	—	$	(703,778	)	$	(131,802	)
	December 31, 2014
	Financial assets:
	Derivatives not designated as hedging instruments	$	10,080	$	—		$	—	$	10,080	$	—		$	10,080
	Total	$	10,080	$	—		$	—	$	10,080	$	—		$	10,080
	Financial liabilities:
	Derivatives not designated as hedging instruments	$	10,200	$	(120	)	$	10,080	$	120	$	(16,734	)	$	(6,534	)
	Repurchase agreements		563,627		—			563,627		—		(624,578	)		(60,951	)
	Total	$	573,827	$	(120	)	$	573,707	$	120	$	(641,312	)	$	(67,485	)

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Reclassification	Reclassification – Certain amounts in the prior periods’ condensed consolidated financial statements and related footnote disclosures have been reclassified to conform to the current presentation with no impact on previously reported net income or stockholders’ equity.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements — The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. A material estimate that is particularly susceptible to significant change in the near term relates to the determination of the allowance for loan losses. Other significant estimates which may be subject to change include fair value determinations and disclosures, impairment of investments, goodwill, loans, as well as valuation of deferred tax assets, other intangibles and OREO.
Recent Accounting Pronouncements	Recent Accounting Pronouncements— In February 2015, the FASB issued ASU No. 2015-02, “Consolidation (Topic 810): Amendments to the Consolidation Analysis”. The new guidance reduces the number of consolidation models from four to two as well as simplifies the FASB Accounting Standards Codification and improves GAAP by placing more of an emphasis on risk of loss when determining a controlling financial interest, reducing the frequency of the application of related party guidance when determining a controlling financial interest in a variable interest entity (VIE) and changing the consolidation conclusions for public and private companies in several industries that typically make use of VIEs. ASU 2015-02 will be effective for the first interim period within annual reporting periods beginning after December 15, 2016. Early adoption is permitted. The adoption of this guidance is not expected to have a material impact on the Company’s consolidated financial statements.
Fair Value Hierarchy	Fair Value Hierarchy
	Fair value is the exchange price that would be received for an asset or paid to transfer a liability (exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date.
	The following disclosure provides the fair value information for financial assets and liabilities as of March 31, 2015. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels (Level 1, Level 2, and Level 3).
		•	Level 1 — Valuation is based upon quoted prices for identical instruments traded in active markets.
		•	Level 2 — Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market.
		•	Level 3 — Valuation is generated from model-based techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect the Company’s own estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of option pricing models, discounted cash flows and similar techniques.

Investment_Securities_Tables

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost and Estimated Fair Value of Investment Securities	The majority of securities held are publicly traded, and the estimated fair values were obtained from an independent pricing service based upon market quotes.
		March 31, 2015
		Amortized		Gross		Gross			Fair Value		Total
		Cost		Unrealized		Unrealized					Percent
				Holding		Holding Loss
				Gain
		(Dollars in thousands)
	Investment securities available-for-sale:
	Government agency	$	334,025	$	140	$	(4,299	)	$	329,866		10.89	%
	Residential mortgage-backed securities		1,807,036		49,360		(1,242	)		1,855,154		61.26	%
	CMOs / REMICs - residential		279,918		8,406		(80	)		288,244		9.52	%
	Municipal bonds		528,464		21,910		(530	)		549,844		18.16	%
	Other securities		5,000		181		—			5,181		0.17	%
	Total	$	2,954,443	$	79,997	$	(6,151	)	$	3,028,289		100	%
		December 31, 2014
		Amortized		Gross		Gross			Fair Value		Total
		Cost		Unrealized		Unrealized					Percent
				Holding		Holding
				Gain		Loss
		(Dollars in thousands)
	Investment securities available-for-sale:
	Government agency	$	339,071	$	—	$	(8,228	)	$	330,843		10.55	%
	Residential mortgage-backed securities		1,884,370		36,154		(3,028	)		1,917,496		61.12	%
	CMOs / REMICs - residential		297,318		7,050		(277	)		304,091		9.69	%
	Municipal bonds		557,823		22,463		(645	)		579,641		18.48	%
	Other securities		5,000		87		—			5,087		0.16	%
	Total	$	3,083,582	$	65,754	$	(12,178	)	$	3,137,158		100	%
Summary of Continuous Unrealized Loss Position of Securities	The tables below show the Company’s investment securities’ gross unrealized losses and fair value by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2015 and December 31, 2014. Management has reviewed individual securities to determine whether a decline in fair value below the amortized cost basis is other-than temporary.
		March 31, 2015
		Less Than 12 Months				12 Months or Longer					Total
		Fair Value		Gross		Fair Value			Gross		Fair Value			Gross
				Unrealized					Unrealized					Unrealized
				Holding					Holding					Holding
				Losses					Losses					Losses
		(Dollars in thousands)
	Available-for-sale:
	Government agency	$	14,558	$	3	$	289,548		$	4,296	$	304,106		$	4,299
	Residential mortgage-backed securities		—		—		128,416			1,242		128,416			1,242
	CMOs / REMICs - residential		—		—		6,679			80		6,679			80
	Municipal bonds		4,152		47		23,917			483		28,069			530
	Other securities		—		—		—			—		—			—
	Total	$	18,710	$	50	$	448,560		$	6,101	$	467,270		$	6,151
		December 31, 2014
		Less Than 12 Months				12 Months or Longer					Total
		Fair Value		Gross		Fair Value			Gross		Fair Value			Gross
				Unrealized					Unrealized					Unrealized
				Holding					Holding					Holding
				Losses					Losses					Losses
		(Dollars in thousands)
	Available-for-sale:
	Government agency	$	22,224	$	28	$	307,873		$	8,200	$	330,097		$	8,228
	Residential mortgage-backed securities		19,636		4		145,681			3,024		165,317			3,028
	CMOs / REMICs - residential		—		—		31,143			277		31,143			277
	Municipal bonds		1,953		23		24,812			622		26,765			645
	Other securities		—		—		—			—		—			—
	Total	$	43,813	$	55	$	509,509		$	12,123	$	553,322		$	12,178
Summary of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity	Mortgage-backed securities and CMOs/REMICs are included in maturity categories based upon estimated prepayment speeds.
		March 31, 2015
		Amortized		Fair
		Cost		Value
		(Dollars in thousands)
	Available-for-sale:
	Due in one year or less	$	160,730	$	164,801
	Due after one year through five years		1,946,053		2,009,028
	Due after five years through ten years		727,902		730,599
	Due after ten years		119,758		123,861
	Total	$	2,954,443	$	3,028,289

Acquired_SJB_Assets_and_FDIC_L1

Acquired SJB Assets and FDIC Loss Sharing Asset (Tables)	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
Summary of PCI Loans and Lease Finance Receivables	The following table provides a summary of PCI loans and lease finance receivables by type and their credit quality indicators for the periods indicated.
		March 31, 2015			December 31, 2014
		(Dollars in thousands)
	Commercial and industrial	$	13,988		$	14,605
	SBA		1,073			1,110
	Real estate:
	Commercial real estate		102,445			109,350
	Construction		—			—
	SFR mortgage		197			205
	Dairy & livestock and agribusiness		330			4,890
	Municipal lease finance receivables		—			—
	Consumer and other loans		2,997			3,336
	Gross PCI loans		121,030			133,496
	Less: Purchase accounting discount		(6,612	)		(7,129	)
	Gross PCI loans, net of discount		114,418			126,367
	Less: Allowance for PCI loans losses		—			—
	Net PCI loans	$	114,418		$	126,367
Summary of PCI Loans by Internal Risk Ratings	The following table summarizes PCI loans by internal risk ratings for the periods indicated.
		March 31, 2015			December 31, 2014
		(Dollars in thousands)
	Pass	$	25,483		$	26,706
	Watch list		69,635			77,371
	Special mention		7,148			8,203
	Substandard		18,764			21,216
	Doubtful & loss		—			—
	Total PCI gross loans	$	121,030		$	133,496

Loans_and_Lease_Finance_Receiv1

Loans and Lease Finance Receivables and Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2015
Receivables [Abstract]
Summary of Components of Loan and Lease Finance Receivables, Excluding PCI Loans	The following table provides a summary of the total of loan and lease finance receivables, excluding PCI loans, by type.
			March 31, 2015			December 31, 2014
			(Dollars in thousands)
	Commercial and industrial		$	403,600		$	390,011
	SBA			126,385			134,265
	Real estate:
	Commercial real estate			2,499,183			2,487,803
	Construction			55,346			55,173
	SFR mortgage			205,132			205,124
	Dairy & livestock and agribusiness			173,441			279,173
	Municipal lease finance receivables			76,220			77,834
	Consumer and other loans			70,749			69,884
	Gross loans, excluding PCI loans			3,610,056			3,699,267
	Less: Deferred loan fees, net			(8,451	)		(8,567	)
	Gross loans, excluding PCI loans, net of deferred loan fees			3,601,605			3,690,700
	Less: Allowance for loan losses			(60,709	)		(59,825	)
	Net loans, excluding PCI loans			3,540,896			3,630,875
	PCI Loans			121,030			133,496
	Discount on PCI loans			(6,612	)		(7,129	)
	PCI loans, net			114,418			126,367
	Total loans and lease finance receivables		$	3,655,314		$	3,757,242
Summary of Activity Related to Loans Held-for-Sale	The following table provides a summary of the activity related to loans held-for-sale for the periods presented.
			For the
			Three Months Ended
			March 31,
			2015			2014
			(Dollars in thousands)
	Balance, beginning of period		$	—		$	3,667
	Originations of mortgage loans			—			—
	Sales of mortgage loans			—			—
	Transfer of mortgage loans to held-for-investment			—			—
	Sales of other loans			—			(3,667	)
	Transfers of other loans to held-for-sale			—			—
	Write-down of loans held-for-sale			—			—
	Balance, end of period		$	—		$	—
Summary of Loan, Excluding PCI Loans by Internal Risk Ratings	The following tables summarize each class of loans, excluding PCI Loans, according to our internal risk ratings for the periods presented.
			March 31, 2015
			Pass			Watch List			Special Mention		Substandard			Doubtful & Loss		Total
			(Dollars in thousands)
	Commercial and industrial		$	252,537		$	96,106		$	42,377	$	12,350		$	230	$	403,600
	SBA			80,047			22,423			14,362		8,070			1,483		126,385
	Real estate:
	Commercial real estate
	Owner occupied			551,211			139,446			49,994		17,159			—		757,810
	Non-owner occupied			1,390,414			258,838			37,420		54,701			—		1,741,373
	Construction
	Speculative			27,394			3,101			—		7,651			—		38,146
	Non-speculative			16,579			621			—		—			—		17,200
	SFR mortgage			176,298			18,882			4,285		5,667			—		205,132
	Dairy & livestock and agribusiness			103,616			67,149			2,277		296			103		173,441
	Municipal lease finance receivables			38,562			32,403			5,255		—			—		76,220
	Consumer and other loans			54,900			10,487			2,670		2,595			97		70,749
	Total gross loans, excluding PCI loans		$	2,691,558		$	649,456		$	158,640	$	108,489		$	1,913	$	3,610,056
			December 31, 2014
			Pass			Watch List			Special Mention		Substandard			Doubtful & Loss		Total
			(Dollars in thousands)
	Commercial and industrial		$	234,029		$	105,904		$	33,795	$	16,031		$	252	$	390,011
	SBA			84,769			24,124			15,858		7,920			1,594		134,265
	Real estate:
	Commercial real estate
	Owner occupied			552,072			159,908			46,248		32,139			—		790,367
	Non-owner occupied			1,347,006			241,809			56,353		52,268			—		1,697,436
	Construction
	Speculative			28,310			613			—		7,651			—		36,574
	Non-speculative			18,071			528			—		—			—		18,599
	SFR mortgage			174,311			20,218			2,442		8,153			—		205,124
	Dairy & livestock and agribusiness			174,783			85,660			8,612		10,015			103		279,173
	Municipal lease finance receivables			35,463			22,349			20,022		—			—		77,834
	Consumer and other loans			62,904			2,233			1,789		2,763			195		69,884
	Total gross loans, excluding PCI loans		$	2,711,718		$	663,346		$	185,119	$	136,940		$	2,144	$	3,699,267
Schedule of Balance and Activity Related to Allowance for Loan Losses for Held-for-Investment Loans, Excluding PCI Loans by Portfolio Segment	The following tables present the balance and activity related to the allowance for loan losses for held-for-investment loans, excluding PCI loans, by portfolio segment for the periods presented.
			For the Three Months Ended March 31, 2015
			Ending			Charge-offs			Recoveries		Provision for			Ending
			Balance								Loan Losses			Balance
			December 31,											March 31,
			2014											2015
			(Dollars in thousands)
	Commercial and industrial		$	7,074		$	(134	)	$	35	$	527		$	7,502
	SBA			2,557			(33	)		34		(362	)		2,196
	Real estate:
	Commercial real estate			33,373			—			857		618			34,848
	Construction			988			—			9		46			1,043
	SFR mortgage			2,344			—			185		(104	)		2,425
	Dairy & livestock and agribusiness			5,479			—			99		(1,832	)		3,746
	Municipal lease finance receivables			1,412			—			—		(382	)		1,030
	Consumer and other loans			1,262			(177	)		9		(269	)		825
	Unallocated			5,336			—			—		1,758			7,094
	Total allowance for loan losses		$	59,825		$	(344	)	$	1,228	$	—		$	60,709
			For the Three Months Ended March 31, 2014
			Ending			Charge-offs			Recoveries		(Recapture of)			Ending
			Balance								Provision for			Balance
			December 31,								Loan Losses			March 31,
			2013											2014
			(Dollars in thousands)
	Commercial and industrial		$	8,502		$	(454	)	$	392	$	(2,072	)	$	6,368
	SBA			2,332			—			63		73			2,468
	Real estate:
	Commercial real estate			39,402			—			68		(70	)		39,400
	Construction			1,305			—			778		(1,625	)		458
	SFR mortgage			2,718			—			—		(436	)		2,282
	Dairy & livestock and agribusiness			11,728			—			144		(2,605	)		9,267
	Municipal lease finance receivables			2,335			—			—		(816	)		1,519
	Consumer and other loans			960			(13	)		12		(9	)		950
	Unallocated			5,953			—			—		60			6,013
	Total allowance for loan losses		$	75,235		$	(467	)	$	1,457	$	(7,500	)	$	68,725
Schedule of Recorded Investment in Loans Held-for-Investment, Excluding PCI Loans, and Related Allowance for Loan Losses by Portfolio Segment	The following tables present the recorded investment in loans held-for-investment, excluding PCI loans, and the related allowance for loan losses by portfolio segment, based on the Company’s methodology for determining the allowance for loan losses for the periods presented.
			March 31, 2015
			Recorded Investment in Loans						Allowance for Loan Losses
			Individually			Collectively			Individually		Collectively
			Evaluated for			Evaluated for			Evaluated for		Evaluated for
			Impairment			Impairment			Impairment		Impairment
			(Dollars in thousands)
	Commercial and industrial		$	1,611		$	401,989		$	592	$	6,910
	SBA			3,158			123,227			42		2,154
	Real estate:
	Commercial real estate			41,886			2,457,297			154		34,694
	Construction			7,651			47,695			—		1,043
	SFR mortgage			5,913			199,219			—		2,425
	Dairy & livestock and agribusiness			7,277			166,164			—		3,746
	Municipal lease finance receivables			—			76,220			—		1,030
	Consumer and other loans			881			69,868			6		819
	Unallocated			—			—			—		7,094
	Total		$	68,377		$	3,541,679		$	794	$	59,915
			March 31, 2014
			Recorded Investment in Loans						Allowance for Loan Losses
			Individually			Collectively			Individually		Collectively
			Evaluated for			Evaluated for			Evaluated for		Evaluated for
			Impairment			Impairment			Impairment		Impairment
			(Dollars in thousands)
	Commercial and industrial		$	4,291		$	354,714		$	814	$	5,554
	SBA			1,649			129,999			68		2,400
	Real estate:
	Commercial real estate			33,907			2,160,144			320		39,080
	Construction			26,688			16,218			—		458
	SFR mortgage			11,692			178,207			47		2,235
	Dairy & livestock and agribusiness			27,972			184,985			2,656		6,611
	Municipal lease finance receivables			—			81,041			—		1,519
	Consumer and other loans			397			54,418			96		854
	Unallocated			—			—			—		6,013
	Total		$	106,596		$	3,159,726		$	4,001	$	64,724
Schedule of Recorded Investment in, and Aging of, Past Due and Nonaccrual Loans, Excluding PCI Loans by Type of Loans	The following tables present the recorded investment in the aging of past due and nonaccrual loans, excluding PCI loans, by type of loans for the periods presented.
			March 31, 2015
			30-59			60-89			Total Past		Nonaccrual			Current		Total Loans and
			Days Past			Days Past			Due and		-1					Financing
			Due			Due			Accruing							Receivables
			(Dollars in thousands)
	Commercial and industrial		$	112		$	—		$	112	$	952		$	402,536		403,600
	SBA			—			—			—		2,463			123,922		126,385
	Real estate:
	Commercial real estate
	Owner occupied			35			—			35		2,418			755,357		757,810
	Non-owner occupied			—			—			—		14,369			1,727,004		1,741,373
	Construction
	Speculative			—			—			—		—			38,146		38,146
	Non-speculative			—			—			—		—			17,200		17,200
	SFR mortgage			1,613			—			1,613		2,233			201,286		205,132
	Dairy & livestock and agribusiness			—			—			—		103			173,338		173,441
	Municipal lease finance receivables			—			—			—		—			76,220		76,220
	Consumer and other loans			119			20			139		463			70,147		70,749
	Total gross loans, excluding PCI Loans		$	1,879		$	20		$	1,899	$	23,001		$	3,585,156	$	3,610,056
	-1	As of March 31, 2015, $20.3 million of nonaccruing loans were current, $553,000 were 30-59 days past due, $86,000 were 60-89 days past due and $2.0 million were 90+ days past due.
			December 31, 2014
			30-59			60-89			Total Past		Nonaccrual			Current		Total Loans and
			Days Past			Days Past			Due and		-1					Financing
			Due			Due			Accruing							Receivables
			(Dollars in thousands)
	Commercial and industrial		$	943		$	35		$	978	$	2,308		$	386,725	$	390,011
	SBA			75			—			75		2,481			131,709		134,265
	Real estate:
	Commercial real estate
	Owner occupied			36			86			122		4,072			786,173		790,367
	Non-owner occupied			—			—			—		19,246			1,678,190		1,697,436
	Construction
	Speculative			—			—			—		—			36,574		36,574
	Non-speculative			—			—			—		—			18,599		18,599
	SFR mortgage			425			—			425		3,240			201,459		205,124
	Dairy & livestock and agribusiness			—			—			—		103			279,070		279,173
	Municipal lease finance receivables			—			—			—		—			77,834		77,834
	Consumer and other loans			64			17			81		736			69,067		69,884
	Total gross loans, excluding PCI Loans		$	1,543		$	138		$	1,681	$	32,186		$	3,665,400	$	3,699,267
	-1	As of December 31, 2014, $20.1 million of nonaccruing loans were current, $3.7 million were 30-59 days past due, $8.5 million were 90+ days.
Schedule of Held-for-Investment Loans, Excluding PCI Loans, Individually Evaluated for Impairment by Class of Loans	The following tables present information for held-for-investment loans, excluding PCI loans, individually evaluated for impairment by class of loans, as of and for the periods indicated below.
			As of and For the Three Months Ended
			31-Mar-15
			Recorded			Unpaid			Related		Average			Interest
			Investment			Principal			Allowance		Recorded			Income
						Balance					Investment			Recognized
			(Dollars in thousands)
	With no related allowance recorded:
	Commercial and industrial		$	1,004		$	1,819		$	—	$	1,017		$	8
	SBA			3,117			3,667			—		3,177			13
	Real estate:
	Commercial real estate
	Owner occupied			6,117			7,167			—		6,185			64
	Non-owner occupied			34,808			42,718			—		35,194			350
	Construction
	Speculative			7,651			7,651			—		7,651			96
	Non-speculative			—			—			—		—			—
	SFR mortgage			5,913			6,642			—		5,940			27
	Dairy & livestock and agribusiness			7,277			8,991			—		7,533			85
	Municipal lease finance receivables			—			—			—		—			—
	Consumer and other loans			783			1,289			—		836			4
	Total			66,670			79,944			—		67,533			647
	With a related allowance recorded:
	Commercial and industrial			607			680			592		617			—
	SBA			41			54			42		45			—
	Real estate:
	Commercial real estate
	Owner occupied			—			—			—		—			—
	Non-owner occupied			961			1,278			154		973			—
	Construction
	Speculative			—			—			—		—			—
	Non-speculative			—			—			—		—			—
	SFR mortgage			—			—			—		—			—
	Dairy & livestock and agribusiness			—			—			—		—			—
	Municipal lease finance receivables			—			—			—		—			—
	Consumer and other loans			98			107			6		99			—
	Total			1,707			2,119			794		1,734			—
	Total impaired loans		$	68,377		$	82,063		$	794	$	69,267		$	647
			As of and For the Three Months Ended
			31-Mar-14
			Recorded			Unpaid			Related		Average			Interest
			Investment			Principal			Allowance		Recorded			Income
						Balance					Investment			Recognized
			(Dollars in thousands)
	With no related allowance recorded:
	Commercial and industrial		$	2,592		$	2,862		$	—	$	2,596		$	15
	SBA			1,581			1,997			—		1,634			—
	Real estate:
	Commercial real estate
	Owner occupied			10,108			10,768			—		10,221			117
	Non-owner occupied			21,928			27,740			—		22,103			215
	Construction
	Speculative			17,519			18,407			—		17,550			77
	Non-speculative			9,169			9,169			—		9,184			140
	SFR mortgage			11,214			12,911			—		11,266			26
	Dairy & livestock and agribusiness			16,582			17,430			—		16,902			189
	Municipal lease finance receivables			—			—			—		—			—
	Consumer and other loans			290			295			—		291			—
	Total			90,983			101,579			—		91,747			779
	With a related allowance recorded:
	Commercial and industrial			1,699			2,033			814		1,701			—
	SBA			68			76			68		70			—
	Real estate:
	Commercial real estate
Owner occupied			1,871			2,344			320		1,871			—
Non-owner occupied			—			—			—		—			—
Construction
Speculative			—			—			—		—			—
Non-speculative			—			—			—		—			—
SFR mortgage			478			486			47		479			—
Dairy & livestock and agribusiness			11,390			12,042			2,656		11,608			75
Municipal lease finance receivables			—			—			—		—			—
Consumer and other loans			107			165			96		107			—
Total			15,613			17,146			4,001		15,836			75
Total impaired loans		$	106,596		$	118,725		$	4,001	$	107,583		$	854
		As of December 31, 2014
		Recorded			Unpaid			Related
		Investment			Principal			Allowance
					Balance
		(Dollars in thousands)
With no related allowance recorded:
Commercial and industrial		$	2,391		$	3,624		$	—
SBA			1,853			2,197			—
Real estate:
Commercial real estate
Owner occupied			16,961			18,166			—
Non-owner occupied			30,068			38,156			—
Construction
Speculative			7,651			7,651			—
Non-speculative			—			—			—
SFR mortgage			6,512			7,493			—
Dairy & livestock and agribusiness			15,796			17,587			—
Municipal lease finance receivables			—			—			—
Consumer and other loans			673			1,094			—
Total			81,905			95,968			—
With a related allowance recorded:
Commercial and industrial			629			698			615
SBA			1,327			1,591			296
Real estate:
Commercial real estate
Owner occupied			—			—			—
Non-owner occupied			982			1,278			154
Construction
Speculative			—			—			—
Non-speculative			—			—			—
SFR mortgage			467			484			35
Dairy & livestock and agribusiness			—			—			—
Municipal lease finance receivables			—			—			—
Consumer and other loans			482			508			449
Total			3,887			4,559			1,549
Total impaired loans		$	85,792		$	100,527		$	1,549
Summary of Activity Related to Troubled Debt Restructurings	The following tables provide a summary of the activity related to TDRs for the periods presented.
			For the Three Months March 31,
			2015			2014
			(Dollars in thousands)
	Performing TDRs:
	Beginning balance		$	53,589		$	66,955
	New modifications			—			41
	Payoffs and payments, net			(8,729	)		(602	)
	TDRs returned to accrual status			516			—
	TDRs placed on nonaccrual status			—			—
	Ending balance		$	45,376		$	66,394
			For the Three Months March 31,
			2015			2014
			(Dollars in thousands)
	Nonperforming TDRs:
	Beginning balance		$	20,285		$	25,119
	New modifications (1)			—			—
	Charge-offs			—			—
	Payoffs and payments, net			(2,995	)		(1,151	)
	TDRs returned to accrual status			(516	)		—
	TDRs placed on nonaccrual status			—			—
	Ending balance		$	16,774		$	23,968
Summary of Loans Modified as Troubled Debt Restructurings	The following tables summarize loans modified as troubled debt restructurings for the periods presented.
	Modifications (1)
			For the Three Months Ended March 31, 2015
			Number of			Pre-Modification			Post-Modification		Outstanding Recorded			Financial Effect
			Loans			Outstanding			Outstanding		Investment at			Resulting From
						Recorded			Recorded		March 31, 2015			Modifications (2)
						Investment			Investment
			(Dollars in thousands)
	Commercial and industrial:
	Interest rate reduction			—		$	—		$	—	$	—		$	—
	Change in amortization period or maturity			—			—			—		—			—
	Real estate:
	Commercial real estate:
	Owner occupied
	Interest rate reduction			—			—			—		—			—
	Change in amortization period or maturity			—			—			—		—
	Non-owner occupied
	Interest rate reduction			—			—			—		—			—
	Change in amortization period or maturity			—			—			—		—			—
	Dairy & livestock and agribusiness:
	Interest rate reduction			—			—			—		—			—
	Change in amortization period or maturity			—			—			—		—			—
	Consumer
	Interest rate reduction			—			—			—		—			—
	Total loans			—		$	—		$	—	$	—		$	—
			For the Three Months Ended March 31, 2014
			Number of			Pre-Modification			Post-Modification		Outstanding Recorded			Financial Effect
			Loans			Outstanding			Outstanding		Investment at			Resulting From
						Recorded			Recorded		March 31, 2014			Modifications (2)
						Investment			Investment
			(Dollars in thousands)
	Commercial and industrial:
	Interest rate reduction			—		$	—		$	—	$	—		$	—
	Change in amortization period or maturity			1			41			41		39			—
	Real estate:
	Commercial real estate:
	Owner occupied
	Interest rate reduction			—			—			—		—			—
	Change in amortization period or maturity			—			—			—		—			—
	Non-owner occupied						—
	Interest rate reduction			—			—			—		—
	Change in amortization period or maturity			—			—			—		—			—
	Dairy & livestock and agribusiness:
	Interest rate reduction			—			—			—		—			—
	Change in amortization period or maturity						—
	Consumer
	Interest rate reduction			—			—			—		—			—
	Total loans			1		$	41		$	41	$	39		$	—
	-1	The tables exclude modified loans that were paid off prior to the end of the period.
	-2	Financial effects resulting from modifications represent charge-offs and specific allowance recorded at modification date.

Earnings_Per_Share_Reconciliat1

Earnings Per Share Reconciliation (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Common Share Reconciliation	The table below summarizes earnings per common share and diluted earnings per common share, and reconciles the numerator and denominator of both earnings per common share calculations.
		For the Thee Months Ended March 31,
		2015		2014
		(In thousands, except per share amounts)
	Earnings per common share:
	Net earnings	$	15,833	$	28,661
	Less: Net earnings allocated to restricted stock		81		127
	Net earnings allocated to common shareholders	$	15,752	$	28,534
	Weighted average shares outstanding		105,523		105,192
	Basic earnings per common share	$	0.15	$	0.27
	Diluted earnings per common share:
	Net income allocated to common shareholders	$	15,752	$	28,534
	Weighted average shares outstanding		105,523		105,192
	Incremental shares from assumed exercise of outstanding options		436		599
	Diluted weighted average shares outstanding		105,959		105,791
	Diluted earnings per common share	$	0.15	$	0.27

Fair_Value_Information_Tables

Fair Value Information (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The tables below present the balances of assets and liabilities measured at fair value on a recurring basis for the periods presented.
		Carrying Value at		Quoted Prices in		Significant Other		Significant
				Active Markets		Observable Inputs		Unobservable
				for Identical				Inputs
				Assets
		March 31, 2015		(Level 1)		(Level 2)		(Level 3)
		(Dollars in thousands)
	Description of assets
	Investment securities - AFS:
	Government agency	$	329,866	$	—	$	329,866	$	—
	Residential mortgage-backed securities		1,855,154		—		1,855,154		—
	CMO’s / REMIC’s - residential		288,244		—		288,244		—
	Municipal bonds		549,844		—		549,844		—
	Other securities		5,181		—		5,181		—
	Total investment securities - AFS		3,028,289		—		3,028,289		—
	Interest rate swaps		11,624		—		11,624		—
	Total assets	$	3,039,913	$	—	$	3,039,913	$	—
	Description of liability
	Interest rate swaps	$	11,624	$	—	$	11,624	$	—
	Total liabilities	$	11,624	$	—	$	11,624	$	—
		Carrying Value at		Quoted Prices in		Significant Other		Significant
				Active Markets		Observable Inputs		Unobservable
				for Identical				Inputs
				Assets
		December 31, 2014		(Level 1)		(Level 2)		(Level 3)
		(Dollars in thousands)
	Description of assets
	Investment securities - AFS:
	Government agency	$	330,843	$	—	$	330,843	$	—
	Residential mortgage-backed securities		1,917,496		—		1,917,496		—
	CMO’s / REMIC’s - residential		304,091		—		304,091		—
	Municipal bonds		579,641		—		579,641		—
	Other securities		5,087		—		5,087		—
	Total investment securities - AFS		3,137,158		—		3,137,158		—
	Interest rate swaps		10,080		—		10,080		—
	Total assets	$	3,147,238	$	—	$	3,147,238	$	—
	Description of liability
	Interest rate swaps	$	10,080	$	—	$	10,080	$	—
	Total liabilities	$	10,080	$	—	$	10,080	$	—
Assets and Liabilities Measured at Fair Value on Non-Recurring Basis	the following tables provide the level of valuation assumptions used to determine each adjustment and the carrying value of the related assets for investments that experienced losses during the period.
		Carrying Value at		Quoted Prices in		Significant		Significant		Total Losses
				Active Markets		Other		Unobservable		For the Three
				for Identical		Observable		Inputs		Months Ended
				Assets		Inputs
		March 31, 2015		(Level 1)		(Level 2)		(Level 3)		March 31, 2015
		(Dollars in thousands)
	Description of assets
	Impaired loans, excluding PCI Loans:
	Commercial and industrial	$	—	$	—	$	—	$	—	$	—
	SBA		—		—		—		—		—
	Real estate:
	Commercial real estate		—		—		—		—		—
	Construction		—		—		—		—		—
	SFR mortgage		—		—		—		—		—
	Dairy & livestock and agribusiness		—		—		—		—		—
	Consumer and other loans		209		—		—		209		76
	Other real estate owned		340		—		—		340		33
	Total assets	$	549	$	—	$	—	$	549	$	109
		Carrying Value at		Quoted Prices in		Significant		Significant		Total Losses
				Active Markets		Other		Unobservable		For the Year Ended
				for Identical		Observable		Inputs
				Assets		Inputs
		December 31, 2014		(Level 1)		(Level 2)		(Level 3)		31-Dec-14
		(Dollars in thousands)
	Description of assets
	Impaired loans, excluding PCI Loans:
	Commercial and industrial	$	1,911	$	—	$	—	$	1,911	$	771
	SBA		1,327		—		—		1,327		296
	Real estate:
	Commercial real estate		2,500		—		—		2,500		271
	Construction		—		—		—		—		—
	SFR mortgage		—		—		—		—		—
	Dairy & livestock and agribusiness		103		—		—		103		1,061
	Consumer and other loans		482		—		—		482		447
	Other real estate owned		—		—		—		—		—
	Total assets	$	6,323	$	—	$	—	$	6,323	$	2,846
Estimated Fair Value of Financial Instruments	The use of different market assumptions and/or estimation methodologies may have a material effect on the estimated fair value amounts.
		March 31, 2015
				Estimated Fair Value
		Carrying		Level 1		Level 2		Level 3		Total
		Amount
		(Dollars in thousands)
	Assets
	Total cash and cash equivalents	$	401,372	$	401,372	$	—	$	—	$	401,372
	Interest-earning balances due from depository institutions		25,873		—		25,873		—		25,873
	FHLB stock		25,338		—		25,338		—		25,338
	Investment securities available-for-sale		3,028,289		—		3,028,289		—		3,028,289
	Investment securities held-to-maturity		1,464		—		—		2,040		2,040
	Loans held-for-sale		—		—		—		—		—
	Total loans, net of allowance for loan losses		3,655,314		—		—		3,704,042		3,704,042
	Accrued interest receivable		22,872		—		22,872		—		22,872
	Swaps		11,624		—		11,624		—		11,624
	Liabilities
	Deposits:
	Noninterest-bearing	$	3,126,928	$	3,126,928	$	—	$	—	$	3,126,928
	Interest-bearing		2,770,848		—		2,771,030		—		2,771,030
	Borrowings		560,352		—		560,291		—		560,291
	Junior subordinated debentures		25,774		—		26,016		—		26,016
	Accrued interest payable		306		—		306		—		306
	Swaps		11,624		—		11,624		—		11,624
		December 31, 2014
				Estimated Fair Value
		Carrying		Level 1		Level 2		Level 3		Total
		Amount
		(Dollars in thousands)
	Assets
	Total cash and cash equivalents	$	105,768	$	105,768	$	—	$	—	$	105,768
	Interest-earning balances due from depository institutions		27,118		—		27,118		—		27,118
	FHLB stock		25,338		—		25,338		—		25,338
	Investment securities available-for-sale		3,137,158		—		3,137,158		—		3,137,158
	Investment securities held-to-maturity		1,528		—		—		2,177		2,177
	Loans held-for-sale		—		—		—		—		—
	Total loans, net of allowance for loan losses		3,757,242		—		—		3,794,454		3,794,454
	Accrued interest receivable		23,194		—		23,194		—		23,194
	Swaps		10,080		—		10,080		—		10,080
	Liabilities
	Deposits:
	Noninterest-bearing	$	2,866,365	$	2,866,365	$	—	$	—	$	2,866,365
	Interest-bearing		2,738,293		—		2,739,221		—		2,739,221
	Borrowings		809,106		—		822,607		—		822,607
	Junior subordinated debentures		25,774		—		26,005		—		26,005
	Accrued interest payable		1,161		—		1,161		—		1,161
	Swaps		10,080		—		10,080		—		10,080

Business_Segments_Tables

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information by Segment	The following tables present the operating results and other key financial measures for the individual operating segments for the periods presented.
			For the Three Months Ended March 31, 2015
			Centers		Treasury			Other			Eliminations			Total
			(Dollars in thousands)
	Interest income, including loan fees		$	35,368	$	18,655		$	10,157		$	—		$	64,180
	Credit for funds provided (1)			8,211		—			12,641			(20,852	)		—
	Total interest income			43,579		18,655			22,798			(20,852	)		64,180
	Interest expense			1,663		1,431			77			—			3,171
	Charge for funds used (1)			1,067		14,806			4,979			(20,852	)		—
	Total interest expense			2,730		16,237			5,056			(20,852	)		3,171
	Net interest income			40,849		2,418			17,742			—			61,009
	Provision for loan losses			—		—			—			—			—
	Net interest income after provision for loan losses			40,849		2,418			17,742			—			61,009
	Noninterest income			5,067		—			2,944			—			8,011
	Noninterest expense			11,849		213			18,540			—			30,602
	Debt termination expense			—		13,870			—			—			13,870
	Segment pre-tax profit		$	34,067	$	(11,665	)	$	2,146		$	—		$	24,548
	Segment assets as of March 31, 2015		$	6,216,028	$	3,450,529		$	898,554		$	(3,122,160	)	$	7,442,951
	-1	Credit for funds provided and charges for funds used are eliminated in the condensed consolidated presentation.
			For the Three Months Ended March 31, 2014
			Centers		Treasury			Other			Eliminations			Total
			(Dollars in thousands)
	Interest income, including loan fees		$	33,091	$	16,432		$	11,539		$	—		$	61,062
	Credit for funds provided (1)			7,074		—			11,463			(18,537	)		—
	Total interest income			40,165		16,432			23,002			(18,537	)		61,062
	Interest expense			1,637		2,373			110			—			4,120
	Charge for funds used (1)			1,090		12,797			4,650			(18,537	)		—
	Total interest expense			2,727		15,170			4,760			(18,537	)		4,120
	Net interest income			37,438		1,262			18,242			—			56,942
	Provision for loan losses			—		—			(7,500	)		—			(7,500	)
	Net interest income after provision for loan losses			37,438		1,262			25,742			—			64,442
	Noninterest income			4,782		—			6,716			—			11,498
	Noninterest expense			11,828		196			19,133			—			31,157
	Debt termination expense			—		—			—			—			—
	Segment pre-tax profit		$	30,392	$	1,066		$	13,325		$	—		$	44,783
	Segment assets as of March 31, 2014		$	5,525,494	$	3,264,736		$	843,026		$	(2,730,738	)	$	6,902,518
	-1	Credit for funds provided and charges for funds used are eliminated in the condensed consolidated presentation.

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments	The location of the asset and liability, and their respective fair values are summarized in the table below.
		March 31, 2015
		Asset Derivatives			Liability Derivatives
		Balance Sheet	Fair		Balance Sheet	Fair
		Location	Value		Location	Value
		(Dollars in thousands)
	Derivatives not designated as hedging instruments:
	Interest rate swaps	Other assets	$	11,624	Other liabilities	$	11,624
	Total derivatives		$	11,624		$	11,624
		31-Dec-14
		Asset Derivatives			Liability Derivatives
		Balance Sheet	Fair		Balance Sheet	Fair
		Location	Value		Location	Value
		(Dollars in thousands)
	Derivatives not designated as hedging instruments:
	Interest rate swaps	Other assets	$	10,080	Other liabilities	$	10,080
	Total derivatives		$	10,080		$	10,080

Other_Comprehensive_Income_Los1

Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Summary of Components of Other Comprehensive Income	The tables below provide a summary of the components of other comprehensive income (“OCI”) for the periods presented.
		For the Three Months Ended March 31, 2015
		Before-Tax			Tax Effect		After-Tax
		(Dollars in thousands)
	Investment securities available-for-sale:
	Net change in fair value recorded in accumulated OCI	$	20,270		$	8,514	$	11,756
	Net change	$	20,270		$	8,514	$	11,756
		For the Three Months Ended March 31, 2014
		Before-Tax			Tax Effect		After-Tax
		(Dollars in thousands)
	Investment securities available-for-sale:
	Net change in fair value recorded in accumulated OCI	$	24,781		$	10,407	$	14,374
	Net change	$	24,781		$	10,407	$	14,374
Summary of Change in Accumulated Other Comprehensive Income	The following table provides a summary of the change in accumulated other comprehensive income for the periods presented.
		Investment Securities
		Available-for-Sale
		(Dollars in thousands)
	Balance, January 1, 2015	$	31,075
	Net change in fair value recorded in accumulated OCI		11,756
	Net realized gains reclassified into earnings		—
	Balance, March 31, 2015	$	42,831
		Investment Securities
		Available-for-Sale
		(Dollars in thousands)
	Balance, January 1, 2014	$	(9,330	)
	Net change in fair value recorded in accumulated OCI		14,374
	Net realized gains reclassified into earnings		—
	Balance, March 31, 2014	$	5,044

Balance_Sheet_Offsetting_Table

Balance Sheet Offsetting (Tables)	3 Months Ended
	Mar. 31, 2015
Text Block [Abstract]
Schedule of Balance Sheet Offsetting	The repurchase agreements are not offset in the condensed consolidated balances.
		Gross Amounts		Gross Amounts			Net Amounts of		Gross Amounts Not Offset in					Net Amount
		Recognized in		offset in the			Assets Presented		the Condensed Consolidated
		the Condensed		Condensed			in the Condensed		Balance Sheets
		Consolidated		Consolidated			Consolidated
		Balance Sheets		Balance Sheets			Balance Sheets		Financial		Collateral
									Instruments		Pledged
		(Dollars in thousands)
	March 31, 2015
	Financial assets:
	Derivatives not designated as hedging instruments	$	11,624	$	—		$	—	$	11,624	$	—		$	11,624
	Total	$	11,624	$	—		$	—	$	11,624	$	—		$	11,624
	Financial liabilities:
	Derivatives not designated as hedging instruments	$	11,624	$	—		$	11,624	$	—	$	(16,761	)	$	(5,137	)
	Repurchase agreements		560,352		—			560,352		—		(687,017	)		(126,665	)
	Total	$	571,976	$	—		$	571,976	$	—	$	(703,778	)	$	(131,802	)
	December 31, 2014
	Financial assets:
	Derivatives not designated as hedging instruments	$	10,080	$	—		$	—	$	10,080	$	—		$	10,080
	Total	$	10,080	$	—		$	—	$	10,080	$	—		$	10,080
	Financial liabilities:
	Derivatives not designated as hedging instruments	$	10,200	$	(120	)	$	10,080	$	120	$	(16,734	)	$	(6,534	)
	Repurchase agreements		563,627		—			563,627		—		(624,578	)		(60,951	)
	Total	$	573,827	$	(120	)	$	573,707	$	120	$	(641,312	)	$	(67,485	)

Business_Additional_Informatio

Business - Additional Information (Detail)	Mar. 31, 2015
	FinancialCenters
	Subsidiary
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of inactive subsidiaries	1
Bank operated Business Financial Centers, number	40
Bank operated Commercial Banking Centers, number	7
Bank operated trust office locations, number	3

Investment_Securities_Summary_

Investment Securities - Summary of Amortized Cost and Estimated Fair Value of 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	$2,954,443	$3,083,582
Gross Unrealized Holding Gain	79,997	65,754
Gross Unrealized Holding Loss	-6,151	-12,178
Fair Value	3,028,289	3,137,158
Total Percent	100.00%	100.00%
CMO's / REMIC's - residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	279,918	297,318
Gross Unrealized Holding Gain	8,406	7,050
Gross Unrealized Holding Loss	-80	-277
Fair Value	288,244	304,091
Total Percent	9.52%	9.69%
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	528,464	557,823
Gross Unrealized Holding Gain	21,910	22,463
Gross Unrealized Holding Loss	-530	-645
Fair Value	549,844	579,641
Total Percent	18.16%	18.48%
Government agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	334,025	339,071
Gross Unrealized Holding Gain	140	0
Gross Unrealized Holding Loss	-4,299	-8,228
Fair Value	329,866	330,843
Total Percent	10.89%	10.55%
Residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,807,036	1,884,370
Gross Unrealized Holding Gain	49,360	36,154
Gross Unrealized Holding Loss	-1,242	-3,028
Fair Value	1,855,154	1,917,496
Total Percent	61.26%	61.12%
Other securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,000	5,000
Gross Unrealized Holding Gain	181	87
Gross Unrealized Holding Loss	0	0
Fair Value	$5,181	$5,087
Total Percent	0.17%	0.16%

Investment_Securities_Addition

Investment Securities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Average life of investment grade debt securities, years	3 years 9 months 18 days
Gross unrealized holding losses	$0
Book value of the bond	1,464,000		1,528,000
Credit-related impairment loss on investment securities held-to-maturity	0	0
Investment securities pledged as collateral	2,990,000,000		3,110,000,000
Investment in FHLB stock, impairment losses	0
United States [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities issued by U.S. government percentage	82.00%
Government agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Agency bond callable	140,900,000
CMO's / REMIC's - residential [Member]
Schedule of Available-for-sale Securities [Line Items]
CMOs/REMICs backed by whole loans issued by private-label companies (non-government sponsored)	304,000
Investment security classified as held-to-maturity, number	1
Held-to-Maturity securities, average FICO score	715
Held-to-Maturity securities, acquired price, percentage	98.25%
Average percentage of LTV	71.00%
Average life of investment grade debt securities, years	30 years
Current fair value percentage of Held-to-Maturity security against par value	78.76%
Investment contractual cash flows guaranteed by Government, percentage	99.99%
Investment contractual cash flows guaranteed by banks, percentage	1.00%
Alt-A bond [Member]
Schedule of Available-for-sale Securities [Line Items]
Book value of the bond	1,500,000
Net impairment losses	$1,900,000
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Weighted-average life of investment grade debt securities, years	8 years 4 months 24 days

Investment_Securities_Summary_1

Investment Securities - Summary of Continuous Unrealized Loss Position of Securities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	$18,710	$43,813
Gross Unrealized Holding Losses, Less Than 12 Months	50	55
Fair Value, 12 Months or Longer	448,560	509,509
Gross Unrealized Holding Losses, 12 Months or Longer	6,101	12,123
Fair Value	467,270	553,322
Gross Unrealized Holding Losses	6,151	12,178
CMO's / REMIC's - residential [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	0	0
Gross Unrealized Holding Losses, Less Than 12 Months	0	0
Fair Value, 12 Months or Longer	6,679	31,143
Gross Unrealized Holding Losses, 12 Months or Longer	80	277
Fair Value	6,679	31,143
Gross Unrealized Holding Losses	80	277
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	4,152	1,953
Gross Unrealized Holding Losses, Less Than 12 Months	47	23
Fair Value, 12 Months or Longer	23,917	24,812
Gross Unrealized Holding Losses, 12 Months or Longer	483	622
Fair Value	28,069	26,765
Gross Unrealized Holding Losses	530	645
Government agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	14,558	22,224
Gross Unrealized Holding Losses, Less Than 12 Months	3	28
Fair Value, 12 Months or Longer	289,548	307,873
Gross Unrealized Holding Losses, 12 Months or Longer	4,296	8,200
Fair Value	304,106	330,097
Gross Unrealized Holding Losses	4,299	8,228
Residential mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	0	19,636
Gross Unrealized Holding Losses, Less Than 12 Months	0	4
Fair Value, 12 Months or Longer	128,416	145,681
Gross Unrealized Holding Losses, 12 Months or Longer	1,242	3,024
Fair Value	128,416	165,317
Gross Unrealized Holding Losses	1,242	3,028
Other securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less Than 12 Months	0	0
Gross Unrealized Holding Losses, Less Than 12 Months	0	0
Fair Value, 12 Months or Longer	0	0
Gross Unrealized Holding Losses, 12 Months or Longer	0	0
Fair Value	0	0
Gross Unrealized Holding Losses	$0	$0

Investment_Securities_Summary_2

Investment Securities - Summary of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity (Detail) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$160,730
Due after one year through five years, Amortized Cost	1,946,053
Due after five years through ten years, Amortized Cost	727,902
Due after ten years, Amortized Cost	119,758
Total Available-for-sale Securities, Debt Maturities, Amortized Cost Basis	2,954,443
Due in one year or less, Fair Value	164,801
Due after one year through five years, Fair Value	2,009,028
Due after five years through ten years, Fair Value	730,599
Due after ten years, Fair Value	123,861
Total, Available-for-sale, Fair Value	$3,028,289

Acquired_SJB_Assets_and_FDIC_L2

Acquired SJB Assets and FDIC Loss Sharing Asset - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended
	Oct. 16, 2009	Mar. 31, 2015	Dec. 31, 2014
Business Combinations [Abstract]
Acquisition date		16-Oct-09
After-tax gain included in earnings due to purchase method	$12,300,000
Remaining discount associated with SJB loans		6,600,000
Expected cash flows		4,400,000
Remaining average lives of respective pools loans		3 years 8 months 12 days
Remaining average lives of respective individual loans		9 months 18 days
Allowance for PCI loans losses		$0	$0

Acquired_SJB_Assets_and_FDIC_L3

Acquired SJB Assets and FDIC Loss Sharing Asset - Summary of PCI Loans and Lease Finance Receivables (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Real estate:
Less: Allowance for PCI loans losses	$0	$0
PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	13,988,000	14,605,000
SBA	1,073,000	1,110,000
Real estate:
Commercial real estate	102,445,000	109,350,000
Construction	0	0
SFR mortgage	197,000	205,000
Dairy & livestock and agribusiness	330,000	4,890,000
Municipal lease finance receivables	0	0
Consumer and other loans	2,997,000	3,336,000
Gross PCI loans	121,030,000	133,496,000
Less: Purchase accounting discount	-6,612,000	-7,129,000
Gross PCI loans, net of discount	114,418,000	126,367,000
Less: Allowance for PCI loans losses	0	0
Net PCI loans	$114,418,000	$126,367,000

Acquired_SJB_Assets_and_FDIC_L4

Acquired SJB Assets and FDIC Loss Sharing Asset - Summary of PCI Loans by Internal Risk Ratings (Detail) (PCI Loans [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total PCI gross loans	$121,030	$133,496
Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total PCI gross loans	25,483	26,706
Watch List [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total PCI gross loans	69,635	77,371
Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total PCI gross loans	7,148	8,203
Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total PCI gross loans	18,764	21,216
Doubtful & Loss [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total PCI gross loans	$0	$0

Loans_and_Lease_Finance_Receiv2

Loans and Lease Finance Receivables and Allowance for Loan Losses - Summary of Components of Loan and Lease Finance Receivables, Excluding PCI Loans (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans, excluding PCI loans, net of deferred loan fees	$3,716,023	$3,817,067
Less: Allowance for loan losses	-60,709	-59,825
Total loans and lease finance receivables	3,655,314	3,757,242
Loans, Excluding PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	403,600	390,011
SBA	126,385	134,265
Commercial real estate	2,499,183	2,487,803
Construction	55,346	55,173
SFR mortgage	205,132	205,124
Dairy & livestock and agribusiness	173,441	279,173
Municipal lease finance receivables	76,220	77,834
Consumer and other loans	70,749	69,884
Gross loans, excluding PCI loans	3,610,056	3,699,267
Less: Deferred loan fees, net	-8,451	-8,567
Gross loans, excluding PCI loans, net of deferred loan fees	3,601,605	3,690,700
Less: Allowance for loan losses	-60,709	-59,825	-68,725	-75,235
Net PCI loans	3,540,896	3,630,875
PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	13,988	14,605
PCI Loans	121,030	133,496
SBA	1,073	1,110
Discount on PCI loans	-6,612	-7,129
Commercial real estate	102,445	109,350
Construction	0	0
SFR mortgage	197	205
Dairy & livestock and agribusiness	330	4,890
Municipal lease finance receivables	0	0
Consumer and other loans	2,997	3,336
Net PCI loans	$114,418	$126,367

Loans_and_Lease_Finance_Receiv3

Loans and Lease Finance Receivables and Allowance for Loan Losses - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	SecurityLoan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total fixed rate loans held	$1,810,000,000
Secure borrowings and available lines of credit from FHLB and Federal Reserve Bank	2,820,000,000		2,780,000,000
Impaired, at carrying value	68,377,000	106,596,000	85,792,000
Loans classified as troubled debt restructured	62,200,000
Provision for unfunded loan commitments	500,000	0
Reserve for credit risk for undisbursed commitments	7,200,000		7,700,000
Number of loans	0
Allocation of allowance to troubled debt restructuring	707,000		726,000
Nonaccrual commercial and industrial loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	952,000
Commercial real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of total gross loan portfolio (excluding PCI loans)	69.23%
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of total gross loan portfolio (excluding PCI loans)	1.53%
Nonaccrual dairy and livestock loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	103,000
Impaired loans modified in troubled debt restructure [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired, at carrying value	62,200,000
Loans, Excluding PCI Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial real estate loans	2,499,183,000		2,487,803,000
Dairy & livestock and agribusiness	173,441,000		279,173,000
Impaired, at carrying value			85,800,000
Outstanding balance	23,001,000		32,186,000
Loans, Excluding PCI Loans [Member] | Commercial real estate loans [Member] | Loans secured by farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of total gross loan portfolio (excluding PCI loans)	6.04%		6.66%
Commercial real estate loans	150,900,000		165,600,000
Loans, Excluding PCI Loans [Member] | Commercial real estate loans [Member] | Loans secured by farmland [Member] | Loans secured by Dairy & livestock land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial real estate loans	131,500,000		144,100,000
Loans, Excluding PCI Loans [Member] | Commercial real estate loans [Member] | Loans secured by farmland [Member] | Loans secured by agricultural land [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial real estate loans	19,400,000		21,500,000
Loans, Excluding PCI Loans [Member] | Dairy & livestock and agribusiness [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of total gross loan portfolio (excluding PCI loans)	4.80%		7.55%
Loans, Excluding PCI Loans [Member] | Dairy & livestock loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Dairy & livestock and agribusiness	161,500,000		268,100,000
Loans, Excluding PCI Loans [Member] | Agribusiness loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Dairy & livestock and agribusiness	12,000,000		11,100,000
Nonaccrual commercial real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	16,800,000
Nonaccrual consumer loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	463,000
Nonperforming financing receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired, at carrying value	16,800,000
Loans classified as troubled debt restructured	16,800,000
Performing financing receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired, at carrying value	68,400,000
Loans classified as troubled debt restructured	45,400,000
Number of performing loans	34
Number of loans removed from TDR classification	0	0
Performing financing receivable [Member] | Commercial real estate loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as troubled debt restructured	25,100,000
Number of loans	12
Performing financing receivable [Member] | Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as troubled debt restructured	7,600,000
Number of loans	1
Performing financing receivable [Member] | Dairy & livestock and agribusiness [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as troubled debt restructured	7,200,000
Number of loans	5
Performing financing receivable [Member] | Single-family Residential Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as troubled debt restructured	3,700,000
Number of loans	11
Performing financing receivable [Member] | Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as troubled debt restructured	1,400,000
Number of loans	4
Performing financing receivable [Member] | Consumer and other loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as troubled debt restructured	418,000
Number of loans	1
Nonaccrual single family mortgage loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	2,200,000
Allowance impaired loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans classified as troubled debt restructured	794,000
Allowance impaired non-covered loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired, at carrying value			$1,500,000

Loans_and_Lease_Finance_Receiv4

Loans and Lease Finance Receivables and Allowance for Loan Losses - Summary of Activity Related to Loans Held-for-Sale (Detail) (Loans Held-for-Sale [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Loans Held-for-Sale [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance, beginning of period	$0	$3,667
Originations of mortgage loans	0	0
Sales of mortgage loans	0	0
Transfer of mortgage loans to held-for-investment	0	0
Sales of other loans	0	-3,667
Transfers of other loans to held-for-sale	0	0
Write-down of loans held-for-sale	0	0
Balance, end of period	$0	$0

Loans_and_Lease_Finance_Receiv5

Loans and Lease Finance Receivables and Allowance for Loan Losses - Summary of Loan, Excluding PCI Loans by Internal Risk Ratings (Detail) (Loans, Excluding PCI Loans [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	$403,600	$390,011
SBA	126,385	134,265
Commercial real estate, Owner occupied	757,810	790,367
Commercial real estate, Non-owner occupied	1,741,373	1,697,436
Construction, Speculative	38,146	36,574
Construction, Non-speculative	17,200
Construction, Non-speculative		18,599
SFR mortgage	205,132	205,124
Dairy & livestock and agribusiness	173,441	279,173
Municipal lease finance receivables	76,220	77,834
Consumer and other loans	70,749	69,884
Total gross loans, excluding PCI loans	3,610,056	3,699,267
Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	252,537	234,029
SBA	80,047	84,769
Commercial real estate, Owner occupied	551,211	552,072
Commercial real estate, Non-owner occupied	1,390,414	1,347,006
Construction, Speculative	27,394	28,310
Construction, Non-speculative	16,579
Construction, Non-speculative		18,071
SFR mortgage	176,298	174,311
Dairy & livestock and agribusiness	103,616	174,783
Municipal lease finance receivables	38,562	35,463
Consumer and other loans	54,900	62,904
Total gross loans, excluding PCI loans	2,691,558	2,711,718
Watch List [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	96,106	105,904
SBA	22,423	24,124
Commercial real estate, Owner occupied	139,446	159,908
Commercial real estate, Non-owner occupied	258,838	241,809
Construction, Speculative	3,101	613
Construction, Non-speculative	621
Construction, Non-speculative		528
SFR mortgage	18,882	20,218
Dairy & livestock and agribusiness	67,149	85,660
Municipal lease finance receivables	32,403	22,349
Consumer and other loans	10,487	2,233
Total gross loans, excluding PCI loans	649,456	663,346
Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	42,377	33,795
SBA	14,362	15,858
Commercial real estate, Owner occupied	49,994	46,248
Commercial real estate, Non-owner occupied	37,420	56,353
Construction, Speculative	0	0
Construction, Non-speculative	0
Construction, Non-speculative		0
SFR mortgage	4,285	2,442
Dairy & livestock and agribusiness	2,277	8,612
Municipal lease finance receivables	5,255	20,022
Consumer and other loans	2,670	1,789
Total gross loans, excluding PCI loans	158,640	185,119
Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	12,350	16,031
SBA	8,070	7,920
Commercial real estate, Owner occupied	17,159	32,139
Commercial real estate, Non-owner occupied	54,701	52,268
Construction, Speculative	7,651	7,651
Construction, Non-speculative	0
Construction, Non-speculative		0
SFR mortgage	5,667	8,153
Dairy & livestock and agribusiness	296	10,015
Municipal lease finance receivables	0	0
Consumer and other loans	2,595	2,763
Total gross loans, excluding PCI loans	108,489	136,940
Doubtful & Loss [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and industrial	230	252
SBA	1,483	1,594
Commercial real estate, Owner occupied	0	0
Commercial real estate, Non-owner occupied	0	0
Construction, Speculative	0	0
Construction, Non-speculative	0
Construction, Non-speculative		0
SFR mortgage	0	0
Dairy & livestock and agribusiness	103	103
Municipal lease finance receivables	0	0
Consumer and other loans	97	195
Total gross loans, excluding PCI loans	$1,913	$2,144

Loans_and_Lease_Finance_Receiv6

Loans and Lease Finance Receivables and Allowance for Loan Losses - Schedule of Balance and Activity Related to Allowance for Loan Losses for Held-for-Investment Loans, Excluding PCI Loans by Portfolio Segment (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	$59,825
Provision for (recapture of) loan losses	0	-7,500
Ending Balance	60,709
Loans, Excluding PCI Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	59,825	75,235
Charge-offs	-344	-467
Recoveries	1,228	1,457
Provision for (recapture of) loan losses	0	-7,500
Ending Balance	60,709	68,725
Loans, Excluding PCI Loans [Member] | Commercial and industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	7,074	8,502
Charge-offs	-134	-454
Recoveries	35	392
Provision for (recapture of) loan losses	527	-2,072
Ending Balance	7,502	6,368
Loans, Excluding PCI Loans [Member] | Small Business Administration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	2,557	2,332
Charge-offs	-33	0
Recoveries	34	63
Provision for (recapture of) loan losses	-362	73
Ending Balance	2,196	2,468
Loans, Excluding PCI Loans [Member] | Commercial real estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	33,373	39,402
Charge-offs	0	0
Recoveries	857	68
Provision for (recapture of) loan losses	618	-70
Ending Balance	34,848	39,400
Loans, Excluding PCI Loans [Member] | Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	988	1,305
Charge-offs	0	0
Recoveries	9	778
Provision for (recapture of) loan losses	46	-1,625
Ending Balance	1,043	458
Loans, Excluding PCI Loans [Member] | SFR mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	2,344	2,718
Charge-offs	0	0
Recoveries	185	0
Provision for (recapture of) loan losses	-104	-436
Ending Balance	2,425	2,282
Loans, Excluding PCI Loans [Member] | Dairy & livestock and agribusiness [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	5,479	11,728
Charge-offs	0	0
Recoveries	99	144
Provision for (recapture of) loan losses	-1,832	-2,605
Ending Balance	3,746	9,267
Loans, Excluding PCI Loans [Member] | Municipal lease finance receivables [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	1,412	2,335
Charge-offs	0	0
Recoveries	0	0
Provision for (recapture of) loan losses	-382	-816
Ending Balance	1,030	1,519
Loans, Excluding PCI Loans [Member] | Consumer and other loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	1,262	960
Charge-offs	-177	-13
Recoveries	9	12
Provision for (recapture of) loan losses	-269	-9
Ending Balance	825	950
Loans, Excluding PCI Loans [Member] | Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	5,336	5,953
Charge-offs	0	0
Recoveries	0	0
Provision for (recapture of) loan losses	1,758	60
Ending Balance	$7,094	$6,013

Loans_and_Lease_Finance_Receiv7

Loans and Lease Finance Receivables and Allowance for Loan Losses - Schedule of Recorded Investment in Loans Held-for-Investment, Excluding PCI Loans, and Related Allowance for Loan Losses by Portfolio Segment (Detail) (Loans, Excluding PCI Loans [Member], USD $)	Mar. 31, 2015	Mar. 31, 2014
In Thousands, unless otherwise specified
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	$68,377	$106,596
Recorded Investment in Loans, Collectively Evaluated for Impairment	3,541,679	3,159,726
Allowance for Loan Losses, Individually Evaluated for Impairment	794	4,001
Allowance for Loan Losses, Collectively Evaluated for Impairment	59,915	64,724
Commercial and industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	1,611	4,291
Recorded Investment in Loans, Collectively Evaluated for Impairment	401,989	354,714
Allowance for Loan Losses, Individually Evaluated for Impairment	592	814
Allowance for Loan Losses, Collectively Evaluated for Impairment	6,910	5,554
Small Business Administration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	3,158	1,649
Recorded Investment in Loans, Collectively Evaluated for Impairment	123,227	129,999
Allowance for Loan Losses, Individually Evaluated for Impairment	42	68
Allowance for Loan Losses, Collectively Evaluated for Impairment	2,154	2,400
Commercial real estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	41,886	33,907
Recorded Investment in Loans, Collectively Evaluated for Impairment	2,457,297	2,160,144
Allowance for Loan Losses, Individually Evaluated for Impairment	154	320
Allowance for Loan Losses, Collectively Evaluated for Impairment	34,694	39,080
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	7,651	26,688
Recorded Investment in Loans, Collectively Evaluated for Impairment	47,695	16,218
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,043	458
SFR mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	5,913	11,692
Recorded Investment in Loans, Collectively Evaluated for Impairment	199,219	178,207
Allowance for Loan Losses, Individually Evaluated for Impairment	0	47
Allowance for Loan Losses, Collectively Evaluated for Impairment	2,425	2,235
Dairy & livestock and agribusiness [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	7,277	27,972
Recorded Investment in Loans, Collectively Evaluated for Impairment	166,164	184,985
Allowance for Loan Losses, Individually Evaluated for Impairment	0	2,656
Allowance for Loan Losses, Collectively Evaluated for Impairment	3,746	6,611
Municipal lease finance receivables [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	76,220	81,041
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,030	1,519
Consumer and other loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	881	397
Recorded Investment in Loans, Collectively Evaluated for Impairment	69,868	54,418
Allowance for Loan Losses, Individually Evaluated for Impairment	6	96
Allowance for Loan Losses, Collectively Evaluated for Impairment	819	854
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment in Loans, Individually Evaluated for Impairment	0	0
Recorded Investment in Loans, Collectively Evaluated for Impairment	0	0
Allowance for Loan Losses, Individually Evaluated for Impairment	0	0
Allowance for Loan Losses, Collectively Evaluated for Impairment	$7,094	$6,013

Loans_and_Lease_Finance_Receiv8

Loans and Lease Finance Receivables and Allowance for Loan Losses - Schedule of Recorded Investment in, and Aging of, Past Due and Nonaccrual Loans, Excluding PCI Loans by Type of Loans (Detail) (Loans, Excluding PCI Loans [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	$1,879,000	$1,543,000
60-89 Days Past Due	20,000	138,000
Total Past Due and Accruing	1,899,000	1,681,000
Nonaccrual	23,001,000	32,186,000
Current	3,585,156,000	3,665,400,000
Gross loans, excluding PCI loans	3,610,056,000	3,699,267,000
Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	112,000	943,000
60-89 Days Past Due	0	35,000
Total Past Due and Accruing	112,000	978,000
Nonaccrual	952,000	2,308,000
Current	402,536,000	386,725,000
Gross loans, excluding PCI loans	403,600,000	390,011,000
Small Business Administration [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	0	75,000
60-89 Days Past Due	0	0
Total Past Due and Accruing	0	75,000
Nonaccrual	2,463,000	2,481,000
Current	123,922,000	131,709,000
Gross loans, excluding PCI loans	126,385,000	134,265,000
Commercial real estate Owner occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	35,000	36,000
60-89 Days Past Due	0	86,000
Total Past Due and Accruing	35,000	122,000
Nonaccrual	2,418,000	4,072,000
Current	755,357,000	786,173,000
Gross loans, excluding PCI loans	757,810,000	790,367,000
Commercial real estate Non-owner occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Total Past Due and Accruing	0	0
Nonaccrual	14,369,000	19,246,000
Current	1,727,004,000	1,678,190,000
Gross loans, excluding PCI loans	1,741,373,000	1,697,436,000
Construction Speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Total Past Due and Accruing	0	0
Nonaccrual	0	0
Current	38,146,000	36,574,000
Gross loans, excluding PCI loans	38,146,000	36,574,000
Construction Non-speculative [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Total Past Due and Accruing	0	0
Nonaccrual	0	0
Current	17,200,000	18,599,000
Gross loans, excluding PCI loans	17,200,000	18,599,000
SFR mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	1,613,000	425,000
60-89 Days Past Due	0	0
Total Past Due and Accruing	1,613,000	425,000
Nonaccrual	2,233,000	3,240,000
Current	201,286,000	201,459,000
Gross loans, excluding PCI loans	205,132,000	205,124,000
Dairy & livestock and agribusiness [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Total Past Due and Accruing	0	0
Nonaccrual	103,000	103,000
Current	173,338,000	279,070,000
Gross loans, excluding PCI loans	173,441,000	279,173,000
Municipal lease finance receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Total Past Due and Accruing	0	0
Nonaccrual	0	0
Current	76,220,000	77,834,000
Gross loans, excluding PCI loans	76,220,000	77,834,000
Consumer and other loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
30-59 Days Past Due	119,000	64,000
60-89 Days Past Due	20,000	17,000
Total Past Due and Accruing	139,000	81,000
Nonaccrual	463,000	736,000
Current	70,147,000	69,067,000
Gross loans, excluding PCI loans	$70,749,000	$69,884,000

Loans_and_Lease_Finance_Receiv9

Loans and Lease Finance Receivables and Allowance for Loan Losses - Schedule of Recorded Investment in, and Aging of, Past Due and Nonaccrual Loans, Excluding PCI Loans by Type of Loans (Parenthetical) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Nonaccruing loans, current	$20,300,000	$20,100,000
Nonaccruing loans, 30-59 days past due	553,000	3,700,000
Nonaccruing loans, 60-89 days past due	86,000
Nonaccruing loans, 90+ days past due	$2,000,000	$8,500,000

Recovered_Sheet1

Loans and Lease Finance Receivables and Allowance for Loan Losses - Schedule of Held-for-Investment Loans, Excluding PCI Loans, Individually Evaluated for Impairment by Class of Loans (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, Total impaired loans	$68,377	$106,596	$85,792
Unpaid Principal Balance, Total impaired loans	82,063	118,725	100,527
Related Allowance, Total impaired loans	794	4,001	1,549
Average Recorded Investment, Total impaired loans	69,267	107,583
Interest Income Recognized, Total impaired loans	647	854
Recorded Investment, With no related allowance recorded	66,670	90,983	81,905
Unpaid Principal Balance, With no related allowance recorded	79,944	101,579	95,968
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	67,533	91,747
Interest Income Recognized, With no related allowance recorded	647	779
Recorded Investment, With a related allowance recorded	1,707	15,613	3,887
Unpaid Principal Balance, With a related allowance recorded	2,119	17,146	4,559
Related Allowance, With a related allowance recorded	794	4,001	1,549
Average Recorded Investment, With a related allowance recorded	1,734	15,836
Interest Income Recognized, With a related allowance recorded	0	75
Commercial and industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	1,004	2,592	2,391
Unpaid Principal Balance, With no related allowance recorded	1,819	2,862	3,624
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	1,017	2,596
Interest Income Recognized, With no related allowance recorded	8	15
Recorded Investment, With a related allowance recorded	607	1,699	629
Unpaid Principal Balance, With a related allowance recorded	680	2,033	698
Related Allowance, With a related allowance recorded	592	814	615
Average Recorded Investment, With a related allowance recorded	617	1,701
Interest Income Recognized, With a related allowance recorded	0	0
Small Business Administration [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	3,117	1,581	1,853
Unpaid Principal Balance, With no related allowance recorded	3,667	1,997	2,197
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	3,177	1,634
Interest Income Recognized, With no related allowance recorded	13	0
Recorded Investment, With a related allowance recorded	41	68	1,327
Unpaid Principal Balance, With a related allowance recorded	54	76	1,591
Related Allowance, With a related allowance recorded	42	68	296
Average Recorded Investment, With a related allowance recorded	45	70
Interest Income Recognized, With a related allowance recorded	0	0
Commercial real estate Owner occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	6,117	10,108	16,961
Unpaid Principal Balance, With no related allowance recorded	7,167	10,768	18,166
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	6,185	10,221
Interest Income Recognized, With no related allowance recorded	64	117
Recorded Investment, With a related allowance recorded	0	1,871	0
Unpaid Principal Balance, With a related allowance recorded	0	2,344	0
Related Allowance, With a related allowance recorded	0	320	0
Average Recorded Investment, With a related allowance recorded	0	1,871
Interest Income Recognized, With a related allowance recorded	0	0
Commercial real estate Non-owner occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	34,808	21,928	30,068
Unpaid Principal Balance, With no related allowance recorded	42,718	27,740	38,156
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	35,194	22,103
Interest Income Recognized, With no related allowance recorded	350	215
Recorded Investment, With a related allowance recorded	961	0	982
Unpaid Principal Balance, With a related allowance recorded	1,278	0	1,278
Related Allowance, With a related allowance recorded	154	0	154
Average Recorded Investment, With a related allowance recorded	973	0
Interest Income Recognized, With a related allowance recorded	0	0
Construction Speculative [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	7,651	17,519
Unpaid Principal Balance, With no related allowance recorded	7,651	18,407
Related Allowance, With no related allowance recorded	0	0
Average Recorded Investment, With no related allowance recorded	7,651	17,550
Interest Income Recognized, With no related allowance recorded	96	77
Recorded Investment, With a related allowance recorded	0	0	0
Unpaid Principal Balance, With a related allowance recorded	0	0	0
Related Allowance, With a related allowance recorded	0	0	0
Average Recorded Investment, With a related allowance recorded	0	0
Interest Income Recognized, With a related allowance recorded	0	0
Construction Non-speculative [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	0	9,169	0
Unpaid Principal Balance, With no related allowance recorded	0	9,169	0
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	0	9,184
Interest Income Recognized, With no related allowance recorded	0	140
Recorded Investment, With a related allowance recorded	0	0	0
Unpaid Principal Balance, With a related allowance recorded	0	0	0
Related Allowance, With a related allowance recorded	0	0	0
Average Recorded Investment, With a related allowance recorded	0	0
Interest Income Recognized, With a related allowance recorded	0	0
SFR mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	5,913	11,214	6,512
Unpaid Principal Balance, With no related allowance recorded	6,642	12,911	7,493
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	5,940	11,266
Interest Income Recognized, With no related allowance recorded	27	26
Recorded Investment, With a related allowance recorded	0	478	467
Unpaid Principal Balance, With a related allowance recorded	0	486	484
Related Allowance, With a related allowance recorded	0	47	35
Average Recorded Investment, With a related allowance recorded	0	479
Interest Income Recognized, With a related allowance recorded	0	0
Dairy & livestock and agribusiness [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	7,277	16,582	15,796
Unpaid Principal Balance, With no related allowance recorded	8,991	17,430	17,587
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	7,533	16,902
Interest Income Recognized, With no related allowance recorded	85	189
Recorded Investment, With a related allowance recorded	0	11,390	0
Unpaid Principal Balance, With a related allowance recorded	0	12,042	0
Related Allowance, With a related allowance recorded	0	2,656	0
Average Recorded Investment, With a related allowance recorded	0	11,608
Interest Income Recognized, With a related allowance recorded	0	75
Municipal lease finance receivables [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	0	0	0
Unpaid Principal Balance, With no related allowance recorded	0	0	0
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	0	0
Interest Income Recognized, With no related allowance recorded	0	0
Recorded Investment, With a related allowance recorded	0	0	0
Unpaid Principal Balance, With a related allowance recorded	0	0	0
Related Allowance, With a related allowance recorded	0	0	0
Average Recorded Investment, With a related allowance recorded	0	0
Interest Income Recognized, With a related allowance recorded	0	0
Consumer and other loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded Investment, With no related allowance recorded	783	290	673
Unpaid Principal Balance, With no related allowance recorded	1,289	295	1,094
Related Allowance, With no related allowance recorded	0	0	0
Average Recorded Investment, With no related allowance recorded	836	291
Interest Income Recognized, With no related allowance recorded	4	0
Recorded Investment, With a related allowance recorded	98	107	482
Unpaid Principal Balance, With a related allowance recorded	107	165	508
Related Allowance, With a related allowance recorded	6	96	449
Average Recorded Investment, With a related allowance recorded	99	107
Interest Income Recognized, With a related allowance recorded	$0	$0

Recovered_Sheet2

Loans and Lease Finance Receivables and Allowance for Loan Losses - Schedule of Held-for-Investment Loans, Excluding PCI Loans, Individually Evaluated for Impairment by Class of Loans (Parenthetical) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Receivables [Abstract]
Recorded Investment, With no related allowance recorded	$66,670	$90,983	$81,905
Recorded Investment, With a related allowance recorded	1,707	15,613	3,887
Recorded Investment, Total impaired loans	68,377	106,596	85,792
Unpaid Principal Balance, With no related allowance recorded	79,944	101,579	95,968
Unpaid Principal Balance, With a related allowance recorded	2,119	17,146	4,559
Unpaid Principal Balance, Total impaired loans	82,063	118,725	100,527
Related Allowance, With no related allowance recorded	0	0	0
Related Allowance, With a related allowance recorded	794	4,001	1,549
Related Allowance, Total impaired loans	794	4,001	1,549
Average Recorded Investment, With no related allowance recorded	67,533	91,747
Average Recorded Investment, With a related allowance recorded	1,734	15,836
Average Recorded Investment, Total impaired loans	69,267	107,583
Interest Income Recognized, With no related allowance recorded	647	779
Interest Income Recognized, With a related allowance recorded	0	75
Interest Income Recognized, Total impaired loans	$647	$854

Recovered_Sheet3

Loans and Lease Finance Receivables and Allowance for Loan Losses - Summary of Activity Related to Troubled Debt Restructurings (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Performing TDRs [Member]
Financing Receivable, Modifications [Line Items]
Beginning balance	$53,589	$66,955
New modifications	0	41
Payoffs and payments, net	-8,729	-602
TDRs returned to accrual status	516	0
TDRs placed on nonaccrual status	0	0
Ending balance	45,376	66,394
Nonperforming TDRs [Member]
Financing Receivable, Modifications [Line Items]
Beginning balance	20,285	25,119
New modifications	0	0
Charge-offs	0	0
Payoffs and payments, net	-2,995	-1,151
TDRs returned to accrual status	-516	0
TDRs placed on nonaccrual status	0	0
Ending balance	$16,774	$23,968

Recovered_Sheet4

Loans and Lease Finance Receivables and Allowance for Loan Losses - Summary of Loans Modified as Troubled Debt Restructurings (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
	Contract	Contract
Loans [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	1
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	$0	$41
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	41
Troubled debt restructurings, Outstanding Recorded Investment	0	39
Troubled debt restructurings, Financial Effect Resulting From Modifications	0	0
Commercial and industrial [Member] | Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Outstanding Recorded Investment	0	0
Troubled debt restructurings, Financial Effect Resulting From Modifications	0	0
Commercial and industrial [Member] | Change in amortization period or maturity [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	1
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	41
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	41
Troubled debt restructurings, Outstanding Recorded Investment	0	39
Troubled debt restructurings, Financial Effect Resulting From Modifications	0	0
Commercial real estate Owner occupied [Member] | Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Outstanding Recorded Investment	0	0
Troubled debt restructurings, Financial Effect Resulting From Modifications	0	0
Commercial real estate Owner occupied [Member] | Change in amortization period or maturity [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Outstanding Recorded Investment	0	0
Troubled debt restructurings, Financial Effect Resulting From Modifications		0
Commercial real estate Non-owner occupied [Member] | Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Outstanding Recorded Investment	0	0
Troubled debt restructurings, Financial Effect Resulting From Modifications	0
Commercial real estate Non-owner occupied [Member] | Change in amortization period or maturity [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Outstanding Recorded Investment	0	0
Troubled debt restructurings, Financial Effect Resulting From Modifications	0	0
Dairy & livestock and agribusiness [Member] | Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Outstanding Recorded Investment	0	0
Troubled debt restructurings, Financial Effect Resulting From Modifications	0	0
Dairy & livestock and agribusiness [Member] | Change in amortization period or maturity [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0
Troubled debt restructurings, Outstanding Recorded Investment	0
Troubled debt restructurings, Financial Effect Resulting From Modifications	0
Consumer [Member] | Interest rate reduction [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, Number of Loans	0	0
Troubled debt restructurings, Pre-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Post-Modification Outstanding Recorded Investment	0	0
Troubled debt restructurings, Outstanding Recorded Investment	0	0
Troubled debt restructurings, Financial Effect Resulting From Modifications	$0	$0

Earnings_Per_Share_Reconciliat2

Earnings Per Share Reconciliation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per common share	235,000	130,000

Earnings_Per_Share_Reconciliat3

Earnings Per Share Reconciliation - Schedule of Earnings Per Common Share Reconciliation (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings per common share:
Net earnings	$15,833	$28,661
Less: Net earnings allocated to restricted stock	81	127
Net earnings allocated to common shareholders	15,752	28,534
Weighted average shares outstanding	105,523	105,192
Basic earnings per common share	$0.15	$0.27
Diluted earnings per common share:
Net income allocated to common shareholders	$15,752	$28,534
Weighted average shares outstanding	105,523	105,192
Incremental shares from assumed exercise of outstanding options	436	599
Diluted weighted average shares outstanding	105,959	105,791
Diluted earnings per common share	$0.15	$0.27

Fair_Value_Information_Additio

Fair Value Information - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair value assets transfers from Level 1 to Level 2	0	$0
Fair value assets transfers from Level 2 to Level 1	0	$0
Minimum [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Term of interest rate swap contracts by the counterparty, years	3 years
Maximum [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Term of interest rate swap contracts by the counterparty, years	30 years

Fair_Value_Information_Assets_

Fair Value Information - Assets and Liabilities 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]
Interest rate swaps	$571,976	$573,707
Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	11,624	10,080
Interest rate swaps	11,624	10,080
Fair Value on Recurring Basis [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Total liabilities	0	0
Fair Value on Recurring Basis [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	3,039,913	3,147,238
Total liabilities	11,624	10,080
Fair Value on Recurring Basis [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	0	0
Total liabilities	0	0
Fair Value on Recurring Basis [Member] | Government agency [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Government agency [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	329,866	330,843
Fair Value on Recurring Basis [Member] | Government agency [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Residential mortgage backed securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0
Fair Value on Recurring Basis [Member] | Residential mortgage backed securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	1,855,154
Fair Value on Recurring Basis [Member] | Residential mortgage backed securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0
Fair Value on Recurring Basis [Member] | CMO's / REMIC's - residential [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | CMO's / REMIC's - residential [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	288,244	304,091
Fair Value on Recurring Basis [Member] | CMO's / REMIC's - residential [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Municipal bonds [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Municipal bonds [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	549,844	579,641
Fair Value on Recurring Basis [Member] | Municipal bonds [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Other securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Other securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	5,181	5,087
Fair Value on Recurring Basis [Member] | Other securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Investment securities - AFS [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Investment securities - AFS [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	3,028,289	3,137,158
Fair Value on Recurring Basis [Member] | Investment securities - AFS [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	0	0
Fair Value on Recurring Basis [Member] | Interest rate swaps [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Interest rate swaps	0	0
Fair Value on Recurring Basis [Member] | Interest rate swaps [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	11,624	10,080
Interest rate swaps	11,624	10,080
Fair Value on Recurring Basis [Member] | Interest rate swaps [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	0	0
Interest rate swaps	0	0
Fair Value on Recurring Basis [Member] | Residential mortgage-backed securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS		0
Fair Value on Recurring Basis [Member] | Residential mortgage-backed securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS		1,917,496
Fair Value on Recurring Basis [Member] | Residential mortgage-backed securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS		0
Fair Value on Recurring Basis [Member] | Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	3,039,913	3,147,238
Total liabilities	11,624	10,080
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | Government agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	329,866	330,843
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | Residential mortgage backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	1,855,154
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | CMO's / REMIC's - residential [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	288,244	304,091
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | Municipal bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	549,844	579,641
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	5,181	5,087
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | Investment securities - AFS [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS	3,028,289	3,137,158
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swaps	11,624	10,080
Interest rate swaps	11,624	10,080
Fair Value on Recurring Basis [Member] | Carrying Value [Member] | Residential mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities - AFS		$1,917,496

Fair_Value_Information_Assets_1

Fair Value Information - Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Detail) (Fair Value on Non-Recurring Basis [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Description of assets
Total assets	$109	$2,846
Other real estate owned [Member]
Description of assets
Total assets	33	0
Loans, Excluding PCI Loans [Member] | Commercial and industrial [Member]
Description of assets
Total assets	0	771
Loans, Excluding PCI Loans [Member] | Small Business Administration [Member]
Description of assets
Total assets	0	296
Loans, Excluding PCI Loans [Member] | Commercial real estate [Member]
Description of assets
Total assets	0	271
Loans, Excluding PCI Loans [Member] | Construction [Member]
Description of assets
Total assets	0	0
Loans, Excluding PCI Loans [Member] | SFR mortgage [Member]
Description of assets
Total assets	0	0
Loans, Excluding PCI Loans [Member] | Dairy & livestock and agribusiness [Member]
Description of assets
Total assets	0	1,061
Loans, Excluding PCI Loans [Member] | Consumer and other loans [Member]
Description of assets
Total assets	76	447
Level 1 [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Other real estate owned [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Loans, Excluding PCI Loans [Member] | Commercial and industrial [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Loans, Excluding PCI Loans [Member] | Small Business Administration [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Loans, Excluding PCI Loans [Member] | Commercial real estate [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Loans, Excluding PCI Loans [Member] | Construction [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Loans, Excluding PCI Loans [Member] | SFR mortgage [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Loans, Excluding PCI Loans [Member] | Dairy & livestock and agribusiness [Member]
Description of assets
Total assets	0	0
Level 1 [Member] | Loans, Excluding PCI Loans [Member] | Consumer and other loans [Member]
Description of assets
Total assets	0	0
Level 2 [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Other real estate owned [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Loans, Excluding PCI Loans [Member] | Commercial and industrial [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Loans, Excluding PCI Loans [Member] | Small Business Administration [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Loans, Excluding PCI Loans [Member] | Commercial real estate [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Loans, Excluding PCI Loans [Member] | Construction [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Loans, Excluding PCI Loans [Member] | SFR mortgage [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Loans, Excluding PCI Loans [Member] | Dairy & livestock and agribusiness [Member]
Description of assets
Total assets	0	0
Level 2 [Member] | Loans, Excluding PCI Loans [Member] | Consumer and other loans [Member]
Description of assets
Total assets	0	0
Level 3 [Member]
Description of assets
Total assets	549	6,323
Level 3 [Member] | Other real estate owned [Member]
Description of assets
Total assets	340	0
Level 3 [Member] | Loans, Excluding PCI Loans [Member] | Commercial and industrial [Member]
Description of assets
Total assets	0	1,911
Level 3 [Member] | Loans, Excluding PCI Loans [Member] | Small Business Administration [Member]
Description of assets
Total assets	0	1,327
Level 3 [Member] | Loans, Excluding PCI Loans [Member] | Commercial real estate [Member]
Description of assets
Total assets	0	2,500
Level 3 [Member] | Loans, Excluding PCI Loans [Member] | Construction [Member]
Description of assets
Total assets	0	0
Level 3 [Member] | Loans, Excluding PCI Loans [Member] | SFR mortgage [Member]
Description of assets
Total assets	0	0
Level 3 [Member] | Loans, Excluding PCI Loans [Member] | Dairy & livestock and agribusiness [Member]
Description of assets
Total assets	0	103
Level 3 [Member] | Loans, Excluding PCI Loans [Member] | Consumer and other loans [Member]
Description of assets
Total assets	209	482
Carrying Value [Member]
Description of assets
Total assets	549	6,323
Carrying Value [Member] | Other real estate owned [Member]
Description of assets
Total assets	340	0
Carrying Value [Member] | Loans, Excluding PCI Loans [Member] | Commercial and industrial [Member]
Description of assets
Total assets	0	1,911
Carrying Value [Member] | Loans, Excluding PCI Loans [Member] | Small Business Administration [Member]
Description of assets
Total assets	0	1,327
Carrying Value [Member] | Loans, Excluding PCI Loans [Member] | Commercial real estate [Member]
Description of assets
Total assets	0	2,500
Carrying Value [Member] | Loans, Excluding PCI Loans [Member] | Construction [Member]
Description of assets
Total assets	0	0
Carrying Value [Member] | Loans, Excluding PCI Loans [Member] | SFR mortgage [Member]
Description of assets
Total assets	0	0
Carrying Value [Member] | Loans, Excluding PCI Loans [Member] | Dairy & livestock and agribusiness [Member]
Description of assets
Total assets	0	103
Carrying Value [Member] | Loans, Excluding PCI Loans [Member] | Consumer and other loans [Member]
Description of assets
Total assets	$209	$482

Fair_Value_Information_Estimat

Fair Value Information - Estimated 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
Total cash and cash equivalents	$401,372	$105,768	$421,386	$94,693
Interest-earning balances due from depository institutions	25,873	27,118
FHLB stock	25,338	25,338
Investment securities available-for-sale	3,028,289	3,137,158
Investment securities held-to-maturity	1,464	1,528
Total loans, net of allowance for loan losses	3,655,314	3,757,242
Accrued interest receivable	22,872	23,194
Deposits:
Noninterest-bearing	3,126,928	2,866,365
Interest-bearing	2,770,848	2,738,293
Junior subordinated debentures	25,774	25,774
Accrued interest payable	306	1,161
Swaps	571,976	573,707
Carrying Value [Member]
Assets
Total cash and cash equivalents	401,372	105,768
Interest-earning balances due from depository institutions	25,873	27,118
FHLB stock	25,338	25,338
Investment securities available-for-sale	3,028,289	3,137,158
Investment securities held-to-maturity	1,464	1,528
Loans held-for-sale	0	0
Total loans, net of allowance for loan losses	3,655,314	3,757,242
Accrued interest receivable	22,872	23,194
Swaps	11,624	10,080
Deposits:
Noninterest-bearing	3,126,928	2,866,365
Interest-bearing	2,770,848	2,738,293
Borrowings	560,352	809,106
Junior subordinated debentures	25,774	25,774
Accrued interest payable	306	1,161
Swaps	11,624	10,080
Estimated Fair Value [Member]
Assets
Total cash and cash equivalents	401,372	105,768
Interest-earning balances due from depository institutions	25,873	27,118
FHLB stock	25,338	25,338
Investment securities available-for-sale	3,028,289	3,137,158
Investment securities held-to-maturity	2,040	2,177
Loans held-for-sale	0	0
Total loans, net of allowance for loan losses	3,704,042	3,794,454
Accrued interest receivable	22,872	23,194
Swaps	11,624	10,080
Deposits:
Noninterest-bearing	3,126,928	2,866,365
Interest-bearing	2,771,030	2,739,221
Borrowings	560,291	822,607
Junior subordinated debentures	26,016	26,005
Accrued interest payable	306	1,161
Swaps	11,624	10,080
Estimated Fair Value [Member] | Level 1 [Member]
Assets
Total cash and cash equivalents	401,372	105,768
Interest-earning balances due from depository institutions	0	0
FHLB stock	0	0
Investment securities available-for-sale	0	0
Investment securities held-to-maturity	0	0
Loans held-for-sale	0	0
Total loans, net of allowance for loan losses	0	0
Accrued interest receivable	0	0
Swaps	0	0
Deposits:
Noninterest-bearing	3,126,928	2,866,365
Interest-bearing	0	0
Borrowings	0	0
Junior subordinated debentures	0	0
Accrued interest payable	0	0
Swaps	0	0
Estimated Fair Value [Member] | Level 2 [Member]
Assets
Total cash and cash equivalents	0	0
Interest-earning balances due from depository institutions	25,873	27,118
FHLB stock	25,338	25,338
Investment securities available-for-sale	3,028,289	3,137,158
Investment securities held-to-maturity	0	0
Loans held-for-sale	0	0
Total loans, net of allowance for loan losses	0	0
Accrued interest receivable	22,872	23,194
Swaps	11,624	10,080
Deposits:
Noninterest-bearing	0	0
Interest-bearing	2,771,030	2,739,221
Borrowings	560,291	822,607
Junior subordinated debentures	26,016	26,005
Accrued interest payable	306	1,161
Swaps	11,624	10,080
Estimated Fair Value [Member] | Level 3 [Member]
Assets
Total cash and cash equivalents	0	0
Interest-earning balances due from depository institutions	0	0
FHLB stock	0	0
Investment securities available-for-sale	0	0
Investment securities held-to-maturity	2,040	2,177
Loans held-for-sale	0	0
Total loans, net of allowance for loan losses	3,704,042	3,794,454
Accrued interest receivable	0	0
Swaps	0	0
Deposits:
Noninterest-bearing	0	0
Interest-bearing	0	0
Borrowings	0	0
Junior subordinated debentures	0	0
Accrued interest payable	0	0
Swaps	$0	$0

Business_Segments_Additional_I

Business Segments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015
	Segment
	FinancialCenters
Segment Reporting Information [Line Items]
Number of principal reporting segments	2
Bank operated Business Financial Centers, number	40
Bank operated Commercial Banking Centers, number	7
Consideration of Business Financial and Commercial Banking Centers	1
Subsidiary bank [Member]
Segment Reporting Information [Line Items]
Bank operated Business Financial Centers, number	40
Bank operated Commercial Banking Centers, number	7

Business_Segments_Schedule_of_

Business Segments - Schedule of Segment Reporting Information by Segment (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Interest income, including loan fees	$64,180	$61,062
Credit for funds provided	0	0
Total interest income	64,180	61,062
Interest expense	3,171	4,120
Charge for funds used	0	0
Total interest expense	3,171	4,120
Net interest income	61,009	56,942
Provision for loan losses	0	-7,500
Net interest income after provision for loan losses	61,009	64,442
Noninterest income	8,011	11,498
Noninterest expense	44,472	31,157
Debt termination expense	13,870	0
Earnings before income taxes	24,548	44,783
Segment assets	7,442,951	6,902,518	7,377,920
Operating segments [Member] | Centers [Member]
Segment Reporting Information [Line Items]
Interest income, including loan fees	35,368	33,091
Credit for funds provided	8,211	7,074
Total interest income	43,579	40,165
Interest expense	1,663	1,637
Charge for funds used	1,067	1,090
Total interest expense	2,730	2,727
Net interest income	40,849	37,438
Provision for loan losses	0	0
Net interest income after provision for loan losses	40,849	37,438
Noninterest income	5,067	4,782
Noninterest expense	11,849	11,828
Debt termination expense	0	0
Earnings before income taxes	34,067	30,392
Segment assets	6,216,028	5,525,494
Operating segments [Member] | Treasury [Member]
Segment Reporting Information [Line Items]
Interest income, including loan fees	18,655	16,432
Credit for funds provided	0	0
Total interest income	18,655	16,432
Interest expense	1,431	2,373
Charge for funds used	14,806	12,797
Total interest expense	16,237	15,170
Net interest income	2,418	1,262
Provision for loan losses	0	0
Net interest income after provision for loan losses	2,418	1,262
Noninterest income	0	0
Noninterest expense	213	196
Debt termination expense	13,870	0
Earnings before income taxes	-11,665	1,066
Segment assets	3,450,529	3,264,736
Operating segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Interest income, including loan fees	10,157	11,539
Credit for funds provided	12,641	11,463
Total interest income	22,798	23,002
Interest expense	77	110
Charge for funds used	4,979	4,650
Total interest expense	5,056	4,760
Net interest income	17,742	18,242
Provision for loan losses	0	-7,500
Net interest income after provision for loan losses	17,742	25,742
Noninterest income	2,944	6,716
Noninterest expense	18,540	19,133
Debt termination expense	0	0
Earnings before income taxes	2,146	13,325
Segment assets	898,554	843,026
Eliminations [Member]
Segment Reporting Information [Line Items]
Interest income, including loan fees	0	0
Credit for funds provided	-20,852	-18,537
Total interest income	-20,852	-18,537
Interest expense	0	0
Charge for funds used	-20,852	-18,537
Total interest expense	-20,852	-18,537
Net interest income	0	0
Provision for loan losses	0	0
Net interest income after provision for loan losses	0	0
Noninterest income	0	0
Noninterest expense	0	0
Debt termination expense	0	0
Earnings before income taxes	0	0
Segment assets	($3,122,160)	($2,730,738)

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets and liabilities offset in balance sheet	$0
Total notional amount of the Company's swaps	193,800,000		197,400,000
Gain recognized in the condensed consolidated statements of earnings	$0	$0
Interest-rate swap agreements with customers [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest-rate swap agreements	75

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Fair Value of Derivative Instruments (Detail) (Derivatives not designated as hedging instruments [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	$11,624	$10,080
Other liabilities [Member] | Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	11,624	10,080
Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	11,624	10,080
Other assets [Member] | Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$11,624	$10,080

Other_Comprehensive_Income_Los2

Other Comprehensive Income (Loss) - Summary of Components of Other Comprehensive Income (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Equity [Abstract]
Net change in fair value recorded in accumulated OCI, Before-Tax	$20,270	$24,781
Net change in fair value recorded in accumulated OCI, Tax Effect	8,514	10,407
Net change in fair value recorded in accumulated OCI, After-Tax	11,756	14,374
Net change, Before-Tax	20,270	24,781
Net change, Tax Effect	8,514	10,407
Net change, After-Tax	$11,756	$14,374

Other_Comprehensive_Income_Los3

Other Comprehensive Income (Loss) - Summary of Change in Accumulated Other Comprehensive Income (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Amounts Reclassified Out Of Accumulated Other Comprehensive Income Loss [Abstract]
Beginning balance	$31,075	($9,330)
Net change in fair value recorded in accumulated OCI	11,756	14,374
Net realized gains reclassified into earnings	0	0
Ending balance	$42,831	$5,044

Balance_Sheet_Offsetting_Sched

Balance Sheet Offsetting - Schedule of Balance Sheet Offsetting (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Offsetting Assets Liabilities [Line Items]
Financial liabilities, Gross Amounts Recognized in the Condensed Consolidated Balance Sheets	$571,976	$573,827
Financial liabilities, Gross Amounts offset in the Condensed Consolidated Balance Sheets	0	-120
Financial liabilities, Net Amounts of Assets presented in the Condensed Consolidated Balance Sheets	571,976	573,707
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Financial Instruments	0	120
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Collateral Pledged	-703,778	-641,312
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Net Amount	-131,802	-67,485
Repurchase agreements [Member]
Offsetting Assets Liabilities [Line Items]
Financial liabilities, Gross Amounts Recognized in the Condensed Consolidated Balance Sheets	560,352	563,627
Financial liabilities, Gross Amounts offset in the Condensed Consolidated Balance Sheets	0	0
Financial liabilities, Net Amounts of Assets presented in the Condensed Consolidated Balance Sheets	560,352	563,627
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Financial Instruments	0	0
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Collateral Pledged	-687,017	-624,578
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Net Amount	-126,665	-60,951
Interest rate swaps [Member]
Offsetting Assets Liabilities [Line Items]
Financial assets, Gross Amounts Recognized in the Condensed Consolidated Balance Sheets	11,624	10,080
Financial assets, Gross Amounts offset in the Condensed Consolidated Balance Sheets	0	0
Financial assets, Net Amounts of Assets presented in the Condensed Consolidated Balance Sheets	0	0
Financial assets, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Financial Instruments	11,624	10,080
Financial assets, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Collateral Pledged	0	0
Financial assets, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Net Amount	11,624	10,080
Interest rate swaps [Member] | Derivatives not designated as hedging instruments [Member]
Offsetting Assets Liabilities [Line Items]
Financial assets, Gross Amounts Recognized in the Condensed Consolidated Balance Sheets	11,624	10,080
Financial assets, Gross Amounts offset in the Condensed Consolidated Balance Sheets	0	0
Financial assets, Net Amounts of Assets presented in the Condensed Consolidated Balance Sheets	0	0
Financial assets, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Financial Instruments	11,624	10,080
Financial assets, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Collateral Pledged	0	0
Financial assets, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Net Amount	11,624	10,080
Financial liabilities, Gross Amounts Recognized in the Condensed Consolidated Balance Sheets	11,624	10,200
Financial liabilities, Gross Amounts offset in the Condensed Consolidated Balance Sheets	0	-120
Financial liabilities, Net Amounts of Assets presented in the Condensed Consolidated Balance Sheets	11,624	10,080
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Financial Instruments	0	120
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Collateral Pledged	-16,761	-16,734
Financial liabilities, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets, Net Amount	($5,137)	($6,534)