FAIR VALUES OF FINANCIAL INSTRUMENTS - Carrying Amounts and Estimated Fair Values of Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Financial assets
Cash and cash equivalents	$ 265,402	$ 231,199
Time deposits in financial institutions	1,900banc_TimeDepositsFairValueDisclosure	1,900banc_TimeDepositsFairValueDisclosure
Securities available for sale	393,586us-gaap_AvailableForSaleSecurities	345,695us-gaap_AvailableForSaleSecurities
FHLB and other bank stock	39,844	42,241
Loans held for sale	1,249,370	1,195,834
Loans and leases receivable, net of allowance	4,008,008	4,045,465
Accrued interest receivable	14,970	15,113
Derivative assets	13,555us-gaap_DerivativeAssets	6,379us-gaap_DerivativeAssets
Financial liabilities
Deposits	4,719,344us-gaap_DepositsFairValueDisclosure	4,575,264us-gaap_DepositsFairValueDisclosure
Advances from Federal Home Loan Bank	545,195	633,083
Other borrowings	15,000
Notes payable	98,852us-gaap_NotesPayableFairValueDisclosure	100,788us-gaap_NotesPayableFairValueDisclosure
Derivative liabilities	4,552us-gaap_DerivativeLiabilities	3,235us-gaap_DerivativeLiabilities
Accrued interest payable	2,016	2,044
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets
Cash and cash equivalents	265,402	231,199
Time deposits in financial institutions	1,900	1,900
Securities available for sale	0	0
FHLB and other bank stock	0	0
Loans held for sale	0	0
Loans and leases receivable, net of allowance	0	0
Accrued interest receivable	14,970	15,113
Derivative assets	0	0
Financial liabilities
Deposits	0	0
Advances from Federal Home Loan Bank	0	0
Other borrowings	0
Notes payable	86,750	87,428
Derivative liabilities	0	0
Accrued interest payable	2,016	2,044
Significant Other Observable Inputs (Level 2)
Financial assets
Cash and cash equivalents	0	0
Time deposits in financial institutions	0	0
Securities available for sale	393,586	345,695
FHLB and other bank stock	39,844	42,241
Loans held for sale	1,249,370	1,195,834
Loans and leases receivable, net of allowance	0	0
Accrued interest receivable	0	0
Derivative assets	13,555	6,379
Financial liabilities
Deposits	0	0
Advances from Federal Home Loan Bank	545,195	633,083
Other borrowings	15,000
Notes payable	12,102	13,360
Derivative liabilities	4,552	3,235
Accrued interest payable	0	0
Significant Unobservable Inputs (Level 3)
Financial assets
Cash and cash equivalents	0	0
Time deposits in financial institutions	0	0
Securities available for sale	0	0
FHLB and other bank stock	0	0
Loans held for sale	0	0
Loans and leases receivable, net of allowance	4,008,008	4,045,465
Accrued interest receivable	0	0
Derivative assets	0	0
Financial liabilities
Deposits	4,719,344	4,575,264
Advances from Federal Home Loan Bank	0	0
Other borrowings	0
Notes payable	0	0
Derivative liabilities	0	0
Accrued interest payable	0	0
Carrying Value
Financial assets
Cash and cash equivalents	265,402	231,199
Time deposits in financial institutions	1,900	1,900
Securities available for sale	393,586	345,695
FHLB and other bank stock	39,844	42,241
Loans held for sale	1,240,942	1,187,090
Loans and leases receivable, net of allowance	3,904,370	3,919,642
Accrued interest receivable	14,970	15,113
Derivative assets	13,555	6,379
Financial liabilities
Deposits	4,861,992	4,671,831
Advances from Federal Home Loan Bank	545,000	633,000
Other borrowings	15,000
Notes payable	92,668	93,569
Derivative liabilities	4,552	3,235
Accrued interest payable	$ 2,016	$ 2,044

Investment in Federal Home Loan and Other Banks Stock, Fair Value Disclosure

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Time Deposits, Fair Value Disclosure

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Fair value portion of amount due from customers or clients for goods or services, including trade receivables, that have been delivered or sold in the normal course of business, and amounts due from others, including related parties.

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Fair value portion of accrued expenses.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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No definition available.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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-Topic 942

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Fair value portion of contractual arrangement with a lender under which borrowings can be made up to a specific amount at any point in time.

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-Glossary Line-of-Credit Arrangement

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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No definition available.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Fair value portion of notes payable.

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