The balance of financing receivables that were acquired with deteriorated credit quality.

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A valuation allowance for financing receivables that are expected to be uncollectible.

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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Amount of direct write-downs of financing receivables charged against the allowance.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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Loans, net and allowance for loan losses - Changes in Allowance for Loan Losses Account by Major Classification of Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for loan losses:
Beginning balance				$ 8,651				$ 6,950	$ 8,651	$ 6,950	$ 6,711
Charge-offs									(2,291)	(841)	(817)
Recoveries									454	181	132
Provisions	800us-gaap_ProvisionForLoanAndLeaseLosses	666us-gaap_ProvisionForLoanAndLeaseLosses	1,201us-gaap_ProvisionForLoanAndLeaseLosses	857us-gaap_ProvisionForLoanAndLeaseLosses	1,036us-gaap_ProvisionForLoanAndLeaseLosses	525us-gaap_ProvisionForLoanAndLeaseLosses	500us-gaap_ProvisionForLoanAndLeaseLosses	300us-gaap_ProvisionForLoanAndLeaseLosses	3,524us-gaap_ProvisionForLoanAndLeaseLosses	2,361us-gaap_ProvisionForLoanAndLeaseLosses	924us-gaap_ProvisionForLoanAndLeaseLosses
Ending balance	10,338				8,651				10,338	8,651	6,950
Beginning balance				8,651				6,950	8,651	6,950	6,711
Ending balance: individually evaluated for impairment	2,682				2,024				2,682	2,024	1,226
Charge-offs									(2,291)	(841)	(817)
Ending balance: collectively evaluated for impairment	7,379				6,627				7,379	6,627	5,724
Recoveries									454	181	132
Ending balance: loans acquired with deteriorated credit quality	277								277
Provisions	800us-gaap_ProvisionForLoanAndLeaseLosses	666us-gaap_ProvisionForLoanAndLeaseLosses	1,201us-gaap_ProvisionForLoanAndLeaseLosses	857us-gaap_ProvisionForLoanAndLeaseLosses	1,036us-gaap_ProvisionForLoanAndLeaseLosses	525us-gaap_ProvisionForLoanAndLeaseLosses	500us-gaap_ProvisionForLoanAndLeaseLosses	300us-gaap_ProvisionForLoanAndLeaseLosses	3,524us-gaap_ProvisionForLoanAndLeaseLosses	2,361us-gaap_ProvisionForLoanAndLeaseLosses	924us-gaap_ProvisionForLoanAndLeaseLosses
Loans receivable:
Ending balance	1,209,894				1,176,617				1,209,894	1,176,617	623,530
Ending balance: individually evaluated for impairment	11,807				15,626				11,807	15,626	5,271
Ending balance: collectively evaluated for impairment	1,195,303				1,153,671				1,195,303	1,153,671	618,259
Ending balance: loans acquired with deteriorated credit quality	2,784				7,320				2,784	7,320
Ending balance	1,209,894				1,176,617				1,209,894	1,176,617	623,530
Ending balance	10,338				8,651				10,338	8,651	6,950
Ending balance: individually evaluated for impairment	11,807				15,626				11,807	15,626	5,271
Ending balance: collectively evaluated for impairment	1,195,303				1,153,671				1,195,303	1,153,671	618,259
Ending balance: loans acquired with deteriorated credit quality	2,784				7,320				2,784	7,320
Commercial [Member]
Allowance for loan losses:
Beginning balance				2,008				799	2,008	799	793
Charge-offs									(601)	(5)	(78)
Recoveries									9	1	1
Provisions									905	1,213	83
Ending balance	2,321				2,008				2,321	2,008	799
Beginning balance				2,008				799	2,008	799	793
Ending balance: individually evaluated for impairment	1,072				1,500				1,072	1,500	351
Charge-offs									(601)	(5)	(78)
Ending balance: collectively evaluated for impairment	1,081				508				1,081	508	448
Recoveries									9	1	1
Ending balance: loans acquired with deteriorated credit quality	168								168
Provisions									905	1,213	83
Loans receivable:
Ending balance	319,590				350,680				319,590	350,680	91,724
Ending balance: individually evaluated for impairment	2,595				4,504				2,595	4,504	655
Ending balance: collectively evaluated for impairment	315,642				343,502				315,642	343,502	91,069
Ending balance: loans acquired with deteriorated credit quality	1,353				2,674				1,353	2,674
Ending balance	319,590				350,680				319,590	350,680	91,724
Ending balance	2,321				2,008				2,321	2,008	799
Ending balance: individually evaluated for impairment	2,595				4,504				2,595	4,504	655
Ending balance: collectively evaluated for impairment	315,642				343,502				315,642	343,502	91,069
Ending balance: loans acquired with deteriorated credit quality	1,353				2,674				1,353	2,674
Real Estate Commercial [Member]
Allowance for loan losses:
Beginning balance				2,394				2,304	2,394	2,304	2,294
Charge-offs									(500)	(15)	(33)
Recoveries									292	20	6
Provisions									851	85	37
Ending balance	3,037				2,394				3,037	2,394	2,304
Beginning balance				2,394				2,304	2,394	2,304	2,294
Ending balance: individually evaluated for impairment	805				300				805	300	550
Charge-offs									(500)	(15)	(33)
Ending balance: collectively evaluated for impairment	2,125				2,094				2,125	2,094	1,754
Recoveries									292	20	6
Ending balance: loans acquired with deteriorated credit quality	107								107
Provisions									851	85	37
Loans receivable:
Ending balance	493,481				413,058				493,481	413,058	217,496
Ending balance: individually evaluated for impairment	5,084				7,711				5,084	7,711	2,160
Ending balance: collectively evaluated for impairment	487,024				401,168				487,024	401,168	215,336
Ending balance: loans acquired with deteriorated credit quality	1,373				4,179				1,373	4,179
Ending balance	493,481				413,058				493,481	413,058	217,496
Ending balance	3,037				2,394				3,037	2,394	2,304
Ending balance: individually evaluated for impairment	5,084				7,711				5,084	7,711	2,160
Ending balance: collectively evaluated for impairment	487,024				401,168				487,024	401,168	215,336
Ending balance: loans acquired with deteriorated credit quality	1,373				4,179				1,373	4,179
Real Estate Residential [Member]
Allowance for loan losses:
Beginning balance				3,135				2,981	3,135	2,981	2,855
Charge-offs									(804)	(508)	(431)
Recoveries									38	111	67
Provisions									1,321	551	490
Ending balance	3,690				3,135				3,690	3,135	2,981
Beginning balance				3,135				2,981	3,135	2,981	2,855
Ending balance: individually evaluated for impairment	767				224				767	224	325
Charge-offs									(804)	(508)	(431)
Ending balance: collectively evaluated for impairment	2,921				2,911				2,921	2,911	2,656
Recoveries									38	111	67
Ending balance: loans acquired with deteriorated credit quality	2								2
Provisions									1,321	551	490
Loans receivable:
Ending balance	310,667				322,062				310,667	322,062	261,912
Ending balance: individually evaluated for impairment	4,001				3,321				4,001	3,321	2,425
Ending balance: collectively evaluated for impairment	306,608				318,274				306,608	318,274	259,487
Ending balance: loans acquired with deteriorated credit quality	58				467				58	467
Ending balance	310,667				322,062				310,667	322,062	261,912
Ending balance	3,690				3,135				3,690	3,135	2,981
Ending balance: individually evaluated for impairment	4,001				3,321				4,001	3,321	2,425
Ending balance: collectively evaluated for impairment	306,608				318,274				306,608	318,274	259,487
Ending balance: loans acquired with deteriorated credit quality	58				467				58	467
Consumer [Member]
Allowance for loan losses:
Beginning balance				1,114				866	1,114	866	769
Charge-offs									(386)	(313)	(275)
Recoveries									115	49	58
Provisions									447	512	314
Ending balance	1,290				1,114				1,290	1,114	866
Beginning balance				1,114				866	1,114	866	769
Ending balance: individually evaluated for impairment	38								38
Charge-offs									(386)	(313)	(275)
Ending balance: collectively evaluated for impairment	1,252				1,114				1,252	1,114	866
Recoveries									115	49	58
Provisions									447	512	314
Loans receivable:
Ending balance	86,156				90,817				86,156	90,817	52,398
Ending balance: individually evaluated for impairment	127				90				127	90	31
Ending balance: collectively evaluated for impairment	86,029				90,727				86,029	90,727	52,367
Ending balance	86,156				90,817				86,156	90,817	52,398
Ending balance	1,290				1,114				1,290	1,114	866
Ending balance: individually evaluated for impairment	127				90				127	90	31
Ending balance: collectively evaluated for impairment	$ 86,029				$ 90,727				$ 86,029	$ 90,727	$ 52,367